Merge branch 'master' into BAEL-16646-2

java-numbers-2/README.md

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+## Java Number Cookbooks and Examples
+
+This module contains articles about numbers in Java.
+
+### Relevant Articles
+- [Lossy Conversion in Java](https://www.baeldung.com/java-lossy-conversion)
+- [A Guide to the Java Math Class](https://www.baeldung.com/java-lang-math)
+- [Calculate the Area of a Circle in Java](https://www.baeldung.com/java-calculate-circle-area)
+- [NaN in Java](https://www.baeldung.com/java-not-a-number)
+- [Generating Prime Numbers in Java](https://www.baeldung.com/java-generate-prime-numbers)
+- [Using Math.pow in Java](https://www.baeldung.com/java-math-pow)
+- [Check If a Number Is Prime in Java](https://www.baeldung.com/java-prime-numbers)
+- [Binary Numbers in Java](https://www.baeldung.com/java-binary-numbers)
+- [Finding the Least Common Multiple in Java](https://www.baeldung.com/java-least-common-multiple)
+- [Binary Numbers in Java](https://www.baeldung.com/java-binary-numbers)
+- [Generating Random Numbers in a Range in Java](https://www.baeldung.com/java-generating-random-numbers)
+- [Listing Numbers Within a Range in Java](https://www.baeldung.com/java-listing-numbers-within-a-range)
+- More articles: [[<-- prev]](/../java-numbers)

java-numbers-2/pom.xml

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+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>java-numbers-2</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>java-numbers-2</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>log4j</groupId>
+            <artifactId>log4j</artifactId>
+            <version>${log4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>${org.slf4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>${logback.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>${jmh-core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>${jmh-generator.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-math3</artifactId>
+            <version>${commons-math3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.decimal4j</groupId>
+            <artifactId>decimal4j</artifactId>
+            <version>${decimal4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>java-numbers-2</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+
+        <plugins>
+
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-javadoc-plugin</artifactId>
+                <version>${maven-javadoc-plugin.version}</version>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <profiles>
+        <profile>
+            <id>integration</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <phase>integration-test</phase>
+                                <goals>
+                                    <goal>test</goal>
+                                </goals>
+                                <configuration>
+                                    <includes>
+                                        <include>**/*IntegrationTest.java</include>
+                                    </includes>
+                                </configuration>
+                            </execution>
+                        </executions>
+                        <configuration>
+                            <systemPropertyVariables>
+                                <test.mime>json</test.mime>
+                            </systemPropertyVariables>
+                        </configuration>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+
+    <properties>
+        <commons-math3.version>3.6.1</commons-math3.version>
+        <decimal4j.version>1.0.3</decimal4j.version>
+        <commons-lang3.version>3.5</commons-lang3.version>
+
+        <assertj.version>3.6.1</assertj.version>
+
+        <org.slf4j.version>1.7.21</org.slf4j.version>
+        <logback.version>1.1.7</logback.version>
+
+        <maven-surefire-plugin.version>2.21.0</maven-surefire-plugin.version>
+        <maven-javadoc-plugin.version>3.0.0-M1</maven-javadoc-plugin.version>
+        <maven-jar-plugin.version>3.0.2</maven-jar-plugin.version>
+    </properties>
+</project>

java-numbers-2/src/main/java/com/baeldung/algorithms/primechecker/BigIntegerPrimeChecker.java

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+package com.baeldung.algorithms.primechecker;
+
+import java.math.BigInteger;
+
+public class BigIntegerPrimeChecker implements PrimeChecker<Long>{
+
+    @Override
+    public boolean isPrime(Long number) {
+        BigInteger bigInt = BigInteger.valueOf(number);
+        return bigInt.isProbablePrime(100);
+    }
+
+}

java-numbers-2/src/main/java/com/baeldung/algorithms/primechecker/BruteForcePrimeChecker.java

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+package com.baeldung.algorithms.primechecker;
+
+import java.util.stream.IntStream;
+
+public class BruteForcePrimeChecker implements PrimeChecker<Integer> {
+
+    @Override
+    public boolean isPrime(Integer number) {
+
+        return number > 2 ? IntStream.range(2, number)
+            .noneMatch(n -> (number % n == 0)) : false;
+    }
+
+}

java-numbers-2/src/main/java/com/baeldung/algorithms/primechecker/OptimisedPrimeChecker.java

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+package com.baeldung.algorithms.primechecker;
+
+import java.util.stream.IntStream;
+
+public class OptimisedPrimeChecker implements PrimeChecker<Integer> {
+
+    @Override
+    public boolean isPrime(Integer number) {
+        return number > 2 ? IntStream.rangeClosed(2, (int) Math.sqrt(number))
+            .noneMatch(n -> (number % n == 0)) : false;
+    }
+
+}

java-numbers-2/src/main/java/com/baeldung/algorithms/primechecker/PrimeChecker.java

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+package com.baeldung.algorithms.primechecker;
+
+public interface PrimeChecker <T> {
+    
+    public boolean isPrime( T number );
+}

java-numbers-2/src/main/java/com/baeldung/algorithms/primechecker/PrimesPrimeChecker.java

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+package com.baeldung.algorithms.primechecker;
+
+import org.apache.commons.math3.primes.Primes;
+
+public class PrimesPrimeChecker implements PrimeChecker<Integer>{
+
+    @Override
+    public boolean isPrime(Integer number) {
+        return Primes.isPrime(number);
+    }
+
+}

java-numbers-2/src/main/java/com/baeldung/area/circle/Circle.java

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+package com.baeldung.area.circle;
+
+public class Circle {
+
+    private double radius;
+
+    public Circle(double radius) {
+        this.radius = radius;
+    }
+
+    public double getRadius() {
+        return radius;
+    }
+
+    public void setRadius(double radius) {
+        this.radius = radius;
+    }
+
+    private double calculateArea() {
+        return radius * radius * Math.PI;
+    }
+
+    public String toString() {
+        return "The area of the circle [radius = " + radius + "]: " + calculateArea();
+    }
+}

java-numbers-2/src/main/java/com/baeldung/area/circle/CircleArea.java

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+package com.baeldung.area.circle;
+
+import java.util.InputMismatchException;
+import java.util.Scanner;
+
+public class CircleArea {
+
+    public static void main(String[] args) {
+        if (args.length > 0) {
+            try {
+                double radius = Double.parseDouble(args[0]);
+                calculateArea(radius);
+            } catch (NumberFormatException nfe) {
+                System.out.println("Invalid value for radius");
+                System.exit(0);
+            }
+        }
+
+        try (Scanner scanner = new Scanner(System.in)) {
+            System.out.println("Please enter radius value: ");
+            double radius = scanner.nextDouble();
+            calculateArea(radius);
+        } catch (InputMismatchException e) {
+            System.out.println("Invalid value for radius");
+            System.exit(0);
+        }
+
+        Circle circle = new Circle(7);
+        System.out.println(circle);
+    }
+
+    private static void calculateArea(double radius) {
+        double area = radius * radius * Math.PI;
+        System.out.println("The area of the circle [radius = " + radius + "]: " + area);
+    }
+}

java-numbers-2/src/main/java/com/baeldung/binarynumbers/BinaryNumbers.java

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+package com.baeldung.binarynumbers;
+
+public class BinaryNumbers {
+
+    /**
+     * This method takes a decimal number and convert it into a binary number.
+     * example:- input:10, output:1010
+     *
+     * @param decimalNumber
+     * @return binary number
+     */
+    public Integer convertDecimalToBinary(Integer decimalNumber) {
+
+        if (decimalNumber == 0) {
+            return decimalNumber;
+        }
+
+        StringBuilder binaryNumber = new StringBuilder();
+        Integer quotient = decimalNumber;
+
+        while (quotient > 0) {
+
+            int remainder = quotient % 2;
+            binaryNumber.append(remainder);
+            quotient /= 2;
+        }
+
+        binaryNumber = binaryNumber.reverse();
+        return Integer.valueOf(binaryNumber.toString());
+    }
+
+    /**
+     * This method takes a binary number and convert it into a decimal number.
+     * example:- input:101, output:5
+     *
+     * @param binary number
+     * @return decimal Number
+     */
+    public Integer convertBinaryToDecimal(Integer binaryNumber) {
+
+        Integer decimalNumber = 0;
+        Integer base = 1;
+
+        while (binaryNumber > 0) {
+
+            int lastDigit = binaryNumber % 10;
+            binaryNumber = binaryNumber / 10;
+
+            decimalNumber += lastDigit * base;
+            base = base * 2;
+        }
+        return decimalNumber;
+    }
+
+    /**
+     * This method accepts two binary numbers and returns sum of input numbers.
+     * Example:- firstNum: 101, secondNum: 100, output: 1001
+     *
+     * @param firstNum
+     * @param secondNum
+     * @return addition of input numbers
+     */
+    public Integer addBinaryNumber(Integer firstNum, Integer secondNum) {
+
+        StringBuilder output = new StringBuilder();
+
+        int carry = 0;
+        int temp;
+
+        while (firstNum != 0 || secondNum != 0) {
+
+            temp = (firstNum % 10 + secondNum % 10 + carry) % 2;
+            output.append(temp);
+
+            carry = (firstNum % 10 + secondNum % 10 + carry) / 2;
+
+            firstNum = firstNum / 10;
+            secondNum = secondNum / 10;
+        }
+
+        if (carry != 0) {
+            output.append(carry);
+        }
+
+        return Integer.valueOf(output.reverse()
+            .toString());
+    }
+
+    /**
+    * This method takes two binary number as input and subtract second number from the first number.
+    * example:- firstNum: 1000, secondNum: 11, output: 101
+    * @param firstNum
+    * @param secondNum
+    * @return Result of subtraction of secondNum from first
+    */
+    public Integer substractBinaryNumber(Integer firstNum, Integer secondNum) {
+
+        int onesComplement = Integer.valueOf(getOnesComplement(secondNum));
+        StringBuilder output = new StringBuilder();
+        int carry = 0;
+        int temp;
+
+        while (firstNum != 0 || onesComplement != 0) {
+
+            temp = (firstNum % 10 + onesComplement % 10 + carry) % 2;
+            output.append(temp);
+
+            carry = (firstNum % 10 + onesComplement % 10 + carry) / 2;
+
+            firstNum = firstNum / 10;
+            onesComplement = onesComplement / 10;
+        }
+
+        String additionOfFirstNumAndOnesComplement = output.reverse()
+            .toString();
+
+        if (carry == 1) {
+            return addBinaryNumber(Integer.valueOf(additionOfFirstNumAndOnesComplement), carry);
+        } else {
+            return getOnesComplement(Integer.valueOf(additionOfFirstNumAndOnesComplement));
+        }
+    }
+
+    public Integer getOnesComplement(Integer num) {
+
+        StringBuilder onesComplement = new StringBuilder();
+        while (num > 0) {
+            int lastDigit = num % 10;
+            if (lastDigit == 0) {
+                onesComplement.append(1);
+            } else {
+                onesComplement.append(0);
+            }
+            num = num / 10;
+        }
+        return Integer.valueOf(onesComplement.reverse()
+            .toString());
+    }
+
+}

java-numbers-2/src/main/java/com/baeldung/lcm/BigIntegerLCM.java

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+package com.baeldung.lcm;
+
+import java.math.BigInteger;
+
+public class BigIntegerLCM {
+
+    public static BigInteger lcm(BigInteger number1, BigInteger number2) {
+        BigInteger gcd = number1.gcd(number2);
+        BigInteger absProduct = number1.multiply(number2).abs();
+        return absProduct.divide(gcd);
+    }
+
+}

java-numbers-2/src/main/java/com/baeldung/lcm/EuclideanAlgorithm.java

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+package com.baeldung.lcm;
+
+import java.util.Arrays;
+
+public class EuclideanAlgorithm {
+
+    public static int gcd(int number1, int number2) {
+        if (number1 == 0 || number2 == 0) {
+            return number1 + number2;
+        } else {
+            int absNumber1 = Math.abs(number1);
+            int absNumber2 = Math.abs(number2);
+            int biggerValue = Math.max(absNumber1, absNumber2);
+            int smallerValue = Math.min(absNumber1, absNumber2);
+            return gcd(biggerValue % smallerValue, smallerValue);
+        }
+    }
+
+    public static int lcm(int number1, int number2) {
+        if (number1 == 0 || number2 == 0)
+            return 0;
+        else {
+            int gcd = gcd(number1, number2);
+            return Math.abs(number1 * number2) / gcd;
+        }
+    }
+
+    public static int lcmForArray(int[] numbers) {
+        int lcm = numbers[0];
+        for (int i = 1; i <= numbers.length - 1; i++) {
+            lcm = lcm(lcm, numbers[i]);
+        }
+        return lcm;
+    }
+
+    public static int lcmByLambda(int... numbers) {
+        return Arrays.stream(numbers).reduce(1, (lcmSoFar, currentNumber) -> Math.abs(lcmSoFar * currentNumber) / gcd(lcmSoFar, currentNumber));
+    }
+
+}

java-numbers-2/src/main/java/com/baeldung/lcm/PrimeFactorizationAlgorithm.java

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+package com.baeldung.lcm;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+public class PrimeFactorizationAlgorithm {
+
+    public static Map<Integer, Integer> getPrimeFactors(int number) {
+        int absNumber = Math.abs(number);
+        Map<Integer, Integer> primeFactorsMap = new HashMap<Integer, Integer>();
+        for (int factor = 2; factor <= absNumber; factor++) {
+            while (absNumber % factor == 0) {
+                Integer power = primeFactorsMap.get(factor);
+                if (power == null) {
+                    power = 0;
+                }
+                primeFactorsMap.put(factor, power + 1);
+                absNumber /= factor;
+            }
+        }
+        return primeFactorsMap;
+    }
+
+    public static int lcm(int number1, int number2) {
+        if (number1 == 0 || number2 == 0) {
+            return 0;
+        }
+        Map<Integer, Integer> primeFactorsForNum1 = getPrimeFactors(number1);
+        Map<Integer, Integer> primeFactorsForNum2 = getPrimeFactors(number2);
+        Set<Integer> primeFactorsUnionSet = new HashSet<Integer>(primeFactorsForNum1.keySet());
+        primeFactorsUnionSet.addAll(primeFactorsForNum2.keySet());
+        int lcm = 1;
+        for (Integer primeFactor : primeFactorsUnionSet) {
+            lcm *= Math.pow(primeFactor, Math.max(primeFactorsForNum1.getOrDefault(primeFactor, 0),
+                    primeFactorsForNum2.getOrDefault(primeFactor, 0)));
+        }
+        return lcm;
+    }
+
+}

java-numbers-2/src/main/java/com/baeldung/lcm/SimpleAlgorithm.java

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+package com.baeldung.lcm;
+
+public class SimpleAlgorithm {
+    public static int lcm(int number1, int number2) {
+        if (number1 == 0 || number2 == 0) {
+            return 0;
+        }
+        int absNumber1 = Math.abs(number1);
+        int absNumber2 = Math.abs(number2);
+        int absHigherNumber = Math.max(absNumber1, absNumber2);
+        int absLowerNumber = Math.min(absNumber1, absNumber2);
+        int lcm = absHigherNumber;
+        while (lcm % absLowerNumber != 0) {
+            lcm += absHigherNumber;
+        }
+        return lcm;
+    }
+}

java-numbers-2/src/main/java/com/baeldung/nan/NaNExample.java

@@ -0,0 +1,81 @@
+package com.baeldung.nan;
+
+/**
+ * Sample usage of NaN.
+ *
+ */
+public class NaNExample {
+
+    public static void main(String[] args) {
+        NaNExample naNExample = new NaNExample();
+        naNExample.demo();
+    }
+
+    void demo() {
+        undefined_operations_produce_NaN();
+        operations_with_no_real_results_produce_NaN();
+        operations_with_NaN_produce_NaN();
+        comparison_with_NaN();
+        check_if_a_value_is_NaN();
+        assign_NaN_to_missing_values();
+    }
+
+    void undefined_operations_produce_NaN() {
+        System.out.println("Undefined Operations Produce NaN");
+        final double ZERO = 0;
+        System.out.println("ZERO / ZERO = " + (ZERO / ZERO));
+        System.out.println("INFINITY - INFINITY = " + (Double.POSITIVE_INFINITY - Double.POSITIVE_INFINITY));
+        System.out.println("INFINITY * ZERO = " + (Double.POSITIVE_INFINITY * ZERO));
+        System.out.println();
+    }
+
+    void operations_with_no_real_results_produce_NaN() {
+        System.out.println("Operations with no real results produce NaN");
+        System.out.println("SQUARE ROOT OF -1 = " + Math.sqrt(-1));
+        System.out.println("LOG OF -1 = " + Math.log(-1));
+        System.out.println();
+    }
+
+    void operations_with_NaN_produce_NaN() {
+        System.out.println("Operations with NaN produce NaN");
+        System.out.println("2 + NaN = " + (2 + Double.NaN));
+        System.out.println("2 - NaN = " + (2 - Double.NaN));
+        System.out.println("2 * NaN = " + (2 * Double.NaN));
+        System.out.println("2 / NaN = " + (2 / Double.NaN));
+        System.out.println();
+    }
+
+    void assign_NaN_to_missing_values() {
+        System.out.println("Assign NaN to Missing values");
+        double salaryRequired = Double.NaN;
+        System.out.println(salaryRequired);
+        System.out.println();
+    }
+
+    void comparison_with_NaN() {
+        System.out.println("Comparison with NaN");
+        final double NAN = Double.NaN;
+        System.out.println("NaN == 1 = " + (NAN == 1));
+        System.out.println("NaN > 1 = " + (NAN > 1));
+        System.out.println("NaN < 1 = " + (NAN < 1));
+        System.out.println("NaN != 1 = " + (NAN != 1));
+        System.out.println("NaN == NaN = " + (NAN == NAN));
+        System.out.println("NaN > NaN = " + (NAN > NAN));
+        System.out.println("NaN < NaN = " + (NAN < NAN));
+        System.out.println("NaN != NaN = " + (NAN != NAN));
+        System.out.println();
+    }
+
+    void check_if_a_value_is_NaN() {
+        System.out.println("Check if a value is NaN");
+        double x = 1;
+        System.out.println(x + " is NaN = " + (x != x));
+        System.out.println(x + " is NaN = " + (Double.isNaN(x)));
+
+        x = Double.NaN;
+        System.out.println(x + " is NaN = " + (x != x));
+        System.out.println(x + " is NaN = " + (Double.isNaN(x)));
+        System.out.println();
+    }
+
+}

java-numbers-2/src/main/java/com/baeldung/numbersinrange/NumbersInARange.java

@@ -0,0 +1,36 @@
+package com.baeldung.numbersinrange;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+public class NumbersInARange {
+
+    public List<Integer> getNumbersInRange(int start, int end) {
+        List<Integer> result = new ArrayList<>();
+        for (int i = start; i < end; i++) {
+            result.add(i);
+        }
+        return result;
+    }
+
+    public List<Integer> getNumbersUsingIntStreamRange(int start, int end) {
+        return IntStream.range(start, end)
+          .boxed()
+          .collect(Collectors.toList());
+    }
+
+    public List<Integer> getNumbersUsingIntStreamRangeClosed(int start, int end) {
+        return IntStream.rangeClosed(start, end)
+          .boxed()
+          .collect(Collectors.toList());
+    }
+
+    public List<Integer> getNumbersUsingIntStreamIterate(int start, int limit) {
+        return IntStream.iterate(start, i -> i + 1)
+          .limit(limit)
+          .boxed()
+          .collect(Collectors.toList());
+    }
+}

java-numbers-2/src/main/java/com/baeldung/numbersinrange/RandomNumbersInARange.java

@@ -0,0 +1,22 @@
+package com.baeldung.numbersinrange;
+
+import java.util.Random;
+
+public class RandomNumbersInARange {
+
+    public int getRandomNumber(int min, int max) {
+        return (int) ((Math.random() * (max - min)) + min);
+    }
+
+    public int getRandomNumberUsingNextInt(int min, int max) {
+        Random random = new Random();
+        return random.nextInt(max - min) + min;
+    }
+
+    public int getRandomNumberUsingInts(int min, int max) {
+        Random random = new Random();
+        return random.ints(min, max)
+          .findFirst()
+          .getAsInt();
+    }
+}

java-numbers-2/src/main/java/com/baeldung/pow/PowerExample.java

@@ -0,0 +1,19 @@
+package com.baeldung.pow;
+
+import java.text.DecimalFormat;
+
+public class PowerExample {
+
+    public static void main(String[] args) {
+
+        int intResult = (int) Math.pow(2, 3);
+        System.out.println("Math.pow(2, 3) = " + intResult);
+
+        double dblResult = Math.pow(4.2, 3);
+        System.out.println("Math.pow(4.2, 3) = " + Math.pow(4.2, 3));
+
+        DecimalFormat df = new DecimalFormat(".00");
+        System.out.println("Math.pow(4.2, 3) rounded = " + df.format(dblResult));
+
+    }
+}

java-numbers-2/src/main/java/com/baeldung/prime/PrimeGenerator.java

@@ -0,0 +1,59 @@
+package com.baeldung.prime;
+
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+public class PrimeGenerator {
+    public static List<Integer> sieveOfEratosthenes(int n) {
+        final boolean prime[] = new boolean[n + 1];
+        Arrays.fill(prime, true);
+
+        for (int p = 2; p * p <= n; p++) {
+            if (prime[p]) {
+                for (int i = p * 2; i <= n; i += p)
+                    prime[i] = false;
+            }
+        }
+
+        final List<Integer> primes = new LinkedList<>();
+        for (int i = 2; i <= n; i++) {
+            if (prime[i])
+                primes.add(i);
+        }
+        return primes;
+    }
+
+    public static List<Integer> primeNumbersBruteForce(int max) {
+        final List<Integer> primeNumbers = new LinkedList<Integer>();
+        for (int i = 2; i <= max; i++) {
+            if (isPrimeBruteForce(i)) {
+                primeNumbers.add(i);
+            }
+        }
+        return primeNumbers;
+    }
+
+    private static boolean isPrimeBruteForce(int x) {
+        for (int i = 2; i < x; i++) {
+            if (x % i == 0) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public static List<Integer> primeNumbersTill(int max) {
+        return IntStream.rangeClosed(2, max)
+            .filter(x -> isPrime(x))
+            .boxed()
+            .collect(Collectors.toList());
+    }
+
+    private static boolean isPrime(int x) {
+        return IntStream.rangeClosed(2, (int) (Math.sqrt(x)))
+            .allMatch(n -> x % n != 0);
+    }
+}

java-numbers-2/src/test/java/com/baeldung/algorithms/primechecker/PrimeCheckerUnitTest.java

@@ -0,0 +1,68 @@
+package com.baeldung.algorithms.primechecker;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public class PrimeCheckerUnitTest {
+
+    private final BigIntegerPrimeChecker primeChecker = new BigIntegerPrimeChecker();
+
+    @Test
+    public void whenCheckIsPrime_thenTrue() {
+        assertTrue(primeChecker.isPrime(13l));
+        assertTrue(primeChecker.isPrime(1009L));
+        assertTrue(primeChecker.isPrime(74207281L));
+    }
+
+    @Test
+    public void whenCheckIsPrime_thenFalse() {
+        assertTrue(!primeChecker.isPrime(50L));
+        assertTrue(!primeChecker.isPrime(1001L));
+        assertTrue(!primeChecker.isPrime(74207282L));
+    }
+
+    private final BruteForcePrimeChecker bfPrimeChecker = new BruteForcePrimeChecker();
+
+    @Test
+    public void whenBFCheckIsPrime_thenTrue() {
+        assertTrue(bfPrimeChecker.isPrime(13));
+        assertTrue(bfPrimeChecker.isPrime(1009));
+    }
+
+    @Test
+    public void whenBFCheckIsPrime_thenFalse() {
+        assertFalse(bfPrimeChecker.isPrime(50));
+        assertFalse(bfPrimeChecker.isPrime(1001));
+    }
+
+    private final OptimisedPrimeChecker optimisedPrimeChecker = new OptimisedPrimeChecker();
+
+    @Test
+    public void whenOptCheckIsPrime_thenTrue() {
+        assertTrue(optimisedPrimeChecker.isPrime(13));
+        assertTrue(optimisedPrimeChecker.isPrime(1009));
+    }
+
+    @Test
+    public void whenOptCheckIsPrime_thenFalse() {
+        assertFalse(optimisedPrimeChecker.isPrime(50));
+        assertFalse(optimisedPrimeChecker.isPrime(1001));
+    }
+
+    private final PrimesPrimeChecker primesPrimeChecker = new PrimesPrimeChecker();
+
+    @Test
+    public void whenPrimesCheckIsPrime_thenTrue() {
+        assertTrue(primesPrimeChecker.isPrime(13));
+        assertTrue(primesPrimeChecker.isPrime(1009));
+    }
+
+    @Test
+    public void whenPrimesCheckIsPrime_thenFalse() {
+        assertFalse(primesPrimeChecker.isPrime(50));
+        assertFalse(primesPrimeChecker.isPrime(1001));
+    }
+
+}

java-numbers-2/src/test/java/com/baeldung/binarynumbers/BinaryNumbersUnitTest.java

@@ -0,0 +1,73 @@
+package com.baeldung.binarynumbers;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class BinaryNumbersUnitTest {
+
+    private BinaryNumbers binaryNumbers = new BinaryNumbers();
+
+    @Test
+    public void given_decimalNumber_then_returnBinaryNumber() {
+        assertEquals(Integer.valueOf(1000), binaryNumbers.convertDecimalToBinary(8));
+        assertEquals(Integer.valueOf(10100), binaryNumbers.convertDecimalToBinary(20));
+    }
+
+    @Test
+    public void given_decimalNumber_then_convertToBinaryNumber() {
+        assertEquals("1000", Integer.toBinaryString(8));
+        assertEquals("10100", Integer.toBinaryString(20));
+    }
+
+    @Test
+    public void given_binaryNumber_then_ConvertToDecimalNumber() {
+        assertEquals(8, Integer.parseInt("1000", 2));
+        assertEquals(20, Integer.parseInt("10100", 2));
+    }
+
+    @Test
+    public void given_binaryNumber_then_returnDecimalNumber() {
+        assertEquals(Integer.valueOf(8), binaryNumbers.convertBinaryToDecimal(1000));
+        assertEquals(Integer.valueOf(20), binaryNumbers.convertBinaryToDecimal(10100));
+    }
+
+    @Test
+    public void given_twoBinaryNumber_then_returnAddition() {
+        // adding 4 and 10
+        assertEquals(Integer.valueOf(1110), binaryNumbers.addBinaryNumber(100, 1010));
+
+        // adding 26 and 14
+        assertEquals(Integer.valueOf(101000), binaryNumbers.addBinaryNumber(11010, 1110));
+    }
+
+    @Test
+    public void given_twoBinaryNumber_then_returnSubtraction() {
+        // subtracting 16 from 25
+        assertEquals(Integer.valueOf(1001), binaryNumbers.substractBinaryNumber(11001, 10000));
+
+        // subtracting 29 from 16, the output here is negative
+        assertEquals(Integer.valueOf(1101), binaryNumbers.substractBinaryNumber(10000, 11101));
+    }
+
+    @Test
+    public void given_binaryLiteral_thenReturnDecimalValue() {
+
+        byte five = 0b101;
+        assertEquals((byte) 5, five);
+
+        short three = 0b11;
+        assertEquals((short) 3, three);
+
+        int nine = 0B1001;
+        assertEquals(9, nine);
+
+        long twentyNine = 0B11101;
+        assertEquals(29, twentyNine);
+
+        int minusThirtySeven = -0B100101;
+        assertEquals(-37, minusThirtySeven);
+
+    }
+
+}

java-numbers-2/src/test/java/com/baeldung/java/math/MathUnitTest.java

@@ -0,0 +1,175 @@
+package com.baeldung.java.math;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class MathUnitTest {
+
+    @Test
+    public void whenAbsInteger_thenReturnAbsoluteValue() {
+        assertEquals(5,Math.abs(-5));
+    }
+
+    @Test
+    public void whenMaxBetweenTwoValue_thenReturnMaximum() {
+        assertEquals(10, Math.max(5,10));
+    }
+
+    @Test
+    public void whenMinBetweenTwoValue_thenReturnMinimum() {
+        assertEquals(5, Math.min(5,10));
+    }
+
+    @Test
+    public void whenSignumWithNegativeNumber_thenReturnMinusOne() {
+        assertEquals(-1, Math.signum(-5), 0);
+    }
+
+    @Test
+    public void whenCopySignWithNegativeSign_thenReturnNegativeArgument() {
+        assertEquals(-5, Math.copySign(5,-1), 0);
+    }
+
+    @Test
+    public void whenPow_thenReturnPoweredValue() {
+        assertEquals(25, Math.pow(5,2),0);
+    }
+
+    @Test
+    public void whenSqrt_thenReturnSquareRoot() {
+        assertEquals(5, Math.sqrt(25),0);
+    }
+
+    @Test
+    public void whenCbrt_thenReturnCubeRoot() {
+        assertEquals(5, Math.cbrt(125),0);
+    }
+
+    @Test
+    public void whenExp_thenReturnEulerNumberRaised() {
+        assertEquals(2.718, Math.exp(1),0.1);
+    }
+
+    @Test
+    public void whenExpm1_thenReturnEulerNumberMinusOne() {
+        assertEquals(1.718, Math.expm1(1),0.1);
+    }
+
+    @Test
+    public void whenGetExponent_thenReturnUnbiasedExponent() {
+        assertEquals(8, Math.getExponent(333.3),0);
+        assertEquals(7, Math.getExponent(222.2f),0);
+    }
+
+    @Test
+    public void whenLog_thenReturnValue() {
+        assertEquals(1, Math.log(Math.E),0);
+    }
+
+    @Test
+    public void whenLog10_thenReturnValue() {
+        assertEquals(1, Math.log10(10),0);
+    }
+
+    @Test
+    public void whenLog1p_thenReturnValue() {
+        assertEquals(1.31, Math.log1p(Math.E),0.1);
+    }
+
+    @Test
+    public void whenSin_thenReturnValue() {
+        assertEquals(1, Math.sin(Math.PI/2),0);
+    }
+
+    @Test
+    public void whenCos_thenReturnValue() {
+        assertEquals(1, Math.cos(0),0);
+    }
+
+    @Test
+    public void whenTan_thenReturnValue() {
+        assertEquals(1, Math.tan(Math.PI/4),0.1);
+    }
+
+    @Test
+    public void whenAsin_thenReturnValue() {
+        assertEquals(Math.PI/2, Math.asin(1),0);
+    }
+
+    @Test
+    public void whenAcos_thenReturnValue() {
+        assertEquals(Math.PI/2, Math.acos(0),0);
+    }
+
+    @Test
+    public void whenAtan_thenReturnValue() {
+        assertEquals(Math.PI/4, Math.atan(1),0);
+    }
+
+    @Test
+    public void whenAtan2_thenReturnValue() {
+        assertEquals(Math.PI/4, Math.atan2(1,1),0);
+    }
+
+    @Test
+    public void whenToDegrees_thenReturnValue() {
+        assertEquals(180, Math.toDegrees(Math.PI),0);
+    }
+
+    @Test
+    public void whenToRadians_thenReturnValue() {
+        assertEquals(Math.PI, Math.toRadians(180),0);
+    }
+
+    @Test
+    public void whenCeil_thenReturnValue() {
+        assertEquals(4, Math.ceil(Math.PI),0);
+    }
+
+    @Test
+    public void whenFloor_thenReturnValue() {
+        assertEquals(3, Math.floor(Math.PI),0);
+    }
+
+    @Test
+    public void whenGetExponent_thenReturnValue() {
+        assertEquals(8, Math.getExponent(333.3),0);
+    }
+
+    @Test
+    public void whenIEEERemainder_thenReturnValue() {
+        assertEquals(1.0, Math.IEEEremainder(5,2),0);
+    }
+
+    @Test
+    public void whenNextAfter_thenReturnValue() {
+        assertEquals(1.9499999284744263, Math.nextAfter(1.95f,1),0.0000001);
+    }
+
+    @Test
+    public void whenNextUp_thenReturnValue() {
+        assertEquals(1.9500002, Math.nextUp(1.95f),0.0000001);
+    }
+
+    @Test
+    public void whenRint_thenReturnValue() {
+        assertEquals(2.0, Math.rint(1.95f),0.0);
+    }
+
+    @Test
+    public void whenRound_thenReturnValue() {
+        assertEquals(2.0, Math.round(1.95f),0.0);
+    }
+
+    @Test
+    public void whenScalb_thenReturnValue() {
+        assertEquals(48, Math.scalb(3, 4),0.0);
+    }
+
+    @Test
+    public void whenHypot_thenReturnValue() {
+        assertEquals(5, Math.hypot(4, 3),0.0);
+    }
+
+}

java-numbers-2/src/test/java/com/baeldung/lcm/BigIntegerLCMUnitTest.java

@@ -0,0 +1,18 @@
+package com.baeldung.lcm;
+
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.math.BigInteger;
+
+public class BigIntegerLCMUnitTest {
+
+    @Test
+    public void testLCM() {
+        BigInteger number1 = new BigInteger("12");
+        BigInteger number2 = new BigInteger("18");
+        BigInteger expectedLCM = new BigInteger("36");
+        Assert.assertEquals(expectedLCM, BigIntegerLCM.lcm(number1, number2));
+    }
+}

java-numbers-2/src/test/java/com/baeldung/lcm/EuclideanAlgorithmUnitTest.java

@@ -0,0 +1,27 @@
+package com.baeldung.lcm;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class EuclideanAlgorithmUnitTest {
+
+    @Test
+    public void testGCD() {
+        Assert.assertEquals(6, EuclideanAlgorithm.gcd(12, 18));
+    }
+
+    @Test
+    public void testLCM() {
+        Assert.assertEquals(36, EuclideanAlgorithm.lcm(12, 18));
+    }
+
+    @Test
+    public void testLCMForArray() {
+        Assert.assertEquals(15, EuclideanAlgorithm.lcmForArray(new int[]{3, 5, 15}));
+    }
+
+    @Test
+    public void testLCMByLambdaForArray() {
+        Assert.assertEquals(15, EuclideanAlgorithm.lcmByLambda(new int[]{3, 5, 15}));
+    }
+}

java-numbers-2/src/test/java/com/baeldung/lcm/PrimeFactorizationAlgorithmUnitTest.java

@@ -0,0 +1,30 @@
+package com.baeldung.lcm;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static com.baeldung.lcm.PrimeFactorizationAlgorithm.*;
+
+
+public class PrimeFactorizationAlgorithmUnitTest {
+
+    @Test
+    public void testGetPrimeFactors() {
+        Map<Integer, Integer> expectedPrimeFactorsMapForTwelve = new HashMap<>();
+        expectedPrimeFactorsMapForTwelve.put(2, 2);
+        expectedPrimeFactorsMapForTwelve.put(3, 1);
+        Map<Integer, Integer> expectedPrimeFactorsMapForEighteen = new HashMap<>();
+        expectedPrimeFactorsMapForEighteen.put(2, 1);
+        expectedPrimeFactorsMapForEighteen.put(3, 2);
+        Assert.assertEquals(expectedPrimeFactorsMapForTwelve, getPrimeFactors(12));
+        Assert.assertEquals(expectedPrimeFactorsMapForEighteen, getPrimeFactors(18));
+    }
+
+    @Test
+    public void testLCM() {
+        Assert.assertEquals(36, PrimeFactorizationAlgorithm.lcm(12, 18));
+    }
+}

java-numbers-2/src/test/java/com/baeldung/lcm/SimpleAlgorithmUnitTest.java

@@ -0,0 +1,15 @@
+package com.baeldung.lcm;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import static com.baeldung.lcm.SimpleAlgorithm.*;
+
+public class SimpleAlgorithmUnitTest {
+
+    @Test
+    public void testLCM() {
+        Assert.assertEquals(36, lcm(12, 18));
+    }
+
+}

java-numbers-2/src/test/java/com/baeldung/lossyconversion/ConversionTechniquesUnitTest.java

@@ -0,0 +1,68 @@
+package com.baeldung.lossyconversion;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+public class ConversionTechniquesUnitTest {
+
+    @Test
+    public void testPrimitiveConversion() {
+        
+        long longNum = 24;
+        short shortNum = (short) longNum;
+        assertEquals(24, shortNum);
+
+        double doubleNum = 15.6;
+        int integerNum = (int) doubleNum;
+        assertEquals(15, integerNum);
+        
+        long largeLongNum = 32768;
+        short minShortNum = (short) largeLongNum;
+        assertEquals(-32768, minShortNum);
+        
+        long smallLongNum = -32769;
+        short maxShortNum = (short) smallLongNum;
+        assertEquals(32767, maxShortNum);
+        
+        long maxLong = Long.MAX_VALUE;
+        int minInt = (int) maxLong;
+        assertEquals(-1, minInt);
+        
+        long minLong = Long.MIN_VALUE;
+        int maxInt = (int) minLong;
+        assertEquals(0, maxInt);
+    }
+
+    @Test
+    public void testWrapperToPrimitiveConversion() {
+
+        Float floatNum = 17.564f;
+        long longNum = floatNum.longValue();
+        assertEquals(17, longNum);
+
+        Double doubleNum = 15.9999;
+        longNum = doubleNum.longValue();
+        assertEquals(15, longNum);
+    }
+
+    @Test
+    public void testWrapperToPrimitiveConversionUsingMathRound() {
+
+        Double doubleNum = 15.9999;
+        long longNum = Math.round(doubleNum);
+        assertEquals(16, longNum);
+    }
+    
+    @Test
+    public void testWrapperConversion() {
+
+        Double doubleNum = 10.3;
+        double dbl = doubleNum.doubleValue(); //unboxing
+        int intgr = (int) dbl; //downcasting
+        Integer intNum = Integer.valueOf(intgr);
+        assertEquals(Integer.valueOf(10), intNum);
+    }
+    
+}

java-numbers-2/src/test/java/com/baeldung/numbersinrange/NumbersInARangeUnitTest.java

@@ -0,0 +1,43 @@
+package com.baeldung.numbersinrange;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.Test;
+
+public class NumbersInARangeUnitTest {
+
+    @Test
+    public void givenTheRange1To10_andUsingForLoop_thenExpectCorrectResult() {
+        NumbersInARange numbersInARange = new NumbersInARange();
+        List<Integer> numbers = numbersInARange.getNumbersInRange(1, 10);
+        
+        assertEquals(Arrays.asList(1,2,3,4,5,6,7,8,9), numbers);
+    }
+    
+    @Test
+    public void givenTheRange1To10_andUsingIntStreamRange_thenExpectCorrectResult() {
+        NumbersInARange numbersInARange = new NumbersInARange();
+        List<Integer> numbers = numbersInARange.getNumbersUsingIntStreamRange(1, 10);
+        
+        assertEquals(Arrays.asList(1,2,3,4,5,6,7,8,9), numbers);
+    }
+    
+    @Test
+    public void givenTheRange1To10_andUsingIntStreamRangeClosed_thenExpectCorrectResult() {
+        NumbersInARange numbersInARange = new NumbersInARange();
+        List<Integer> numbers = numbersInARange.getNumbersUsingIntStreamRangeClosed(1, 10);
+        
+        assertEquals(Arrays.asList(1,2,3,4,5,6,7,8,9,10), numbers);
+    }
+    
+    @Test
+    public void givenTheRange1To10_andUsingIntStreamIterate_thenExpectCorrectResult() {
+        NumbersInARange numbersInARange = new NumbersInARange();
+        List<Integer> numbers = numbersInARange.getNumbersUsingIntStreamIterate(1, 10);
+        
+        assertEquals(Arrays.asList(1,2,3,4,5,6,7,8,9,10), numbers);
+    }
+}

java-numbers-2/src/test/java/com/baeldung/numbersinrange/RandomNumbersInARangeUnitTest.java

@@ -0,0 +1,35 @@
+package com.baeldung.numbersinrange;
+
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class RandomNumbersInARangeUnitTest {
+
+    @Test
+    public void givenTheRange1To10_andUsingMathRandom_thenExpectCorrectResult() {
+        RandomNumbersInARange randomNumbersInARange = new RandomNumbersInARange();
+        int number = randomNumbersInARange.getRandomNumber(1, 10);
+
+        assertTrue(number >= 1);
+        assertTrue(number < 10);
+    }
+
+    @Test
+    public void givenTheRange1To10_andUsingRandomInts_thenExpectCorrectResult() {
+        RandomNumbersInARange randomNumbersInARange = new RandomNumbersInARange();
+        int number = randomNumbersInARange.getRandomNumberUsingInts(1, 10);
+
+        assertTrue(number >= 1);
+        assertTrue(number < 10);
+    }
+
+    @Test
+    public void givenTheRange1To10_andUsingRandomNextInt_thenExpectCorrectResult() {
+        RandomNumbersInARange randomNumbersInARange = new RandomNumbersInARange();
+        int number = randomNumbersInARange.getRandomNumberUsingNextInt(1, 10);
+
+        assertTrue(number >= 1);
+        assertTrue(number < 10);
+    }
+}

java-numbers-2/src/test/java/com/baeldung/prime/PrimeGeneratorUnitTest.java

@@ -0,0 +1,29 @@
+package com.baeldung.prime;
+
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static com.baeldung.prime.PrimeGenerator.*;
+import static org.junit.Assert.*;
+
+public class PrimeGeneratorUnitTest {
+    @Test
+    public void whenBruteForced_returnsSuccessfully() {
+        final List<Integer> primeNumbers = primeNumbersBruteForce(20);
+        assertEquals(Arrays.asList(new Integer[] { 2, 3, 5, 7, 11, 13, 17, 19 }), primeNumbers);
+    }
+
+    @Test
+    public void whenOptimized_returnsSuccessfully() {
+        final List<Integer> primeNumbers = primeNumbersTill(20);
+        assertEquals(Arrays.asList(new Integer[] { 2, 3, 5, 7, 11, 13, 17, 19 }), primeNumbers);
+    }
+
+    @Test
+    public void whenSieveOfEratosthenes_returnsSuccessfully() {
+        final List<Integer> primeNumbers = sieveOfEratosthenes(20);
+        assertEquals(Arrays.asList(new Integer[] { 2, 3, 5, 7, 11, 13, 17, 19 }), primeNumbers);
+    }
+}