From 6bbef27bc74d343ec0f9cba60f72a5707fc3071a Mon Sep 17 00:00:00 2001
From: "Kai.Yuan" <kent.yuan@Gmail.com>
Date: Wed, 31 Jan 2024 23:27:16 +0100
Subject: [PATCH] [count-upper-lower] count upper/lowercase letters

---
 .../core-java-string-operations-8/README.md   |   4 +-
 .../core-java-string-operations-8/pom.xml     | 106 ++++++------------
 .../CountUpperAndLowercaseCharsUnitTest.java  |  85 ++++++++++++++
 3 files changed, 121 insertions(+), 74 deletions(-)
 create mode 100644 core-java-modules/core-java-string-operations-8/src/test/java/com/baeldung/countupperandlowercasechars/CountUpperAndLowercaseCharsUnitTest.java

diff --git a/core-java-modules/core-java-string-operations-8/README.md b/core-java-modules/core-java-string-operations-8/README.md
index 2dce44d217..6598a4b9cc 100644
--- a/core-java-modules/core-java-string-operations-8/README.md
+++ b/core-java-modules/core-java-string-operations-8/README.md
@@ -1,2 +1,2 @@
-
-### Relevant Articles:
+### Relevant Articles:
+>>>>>>> be317465c ([count-upper-lower] count upper/lowercase letters)
diff --git a/core-java-modules/core-java-string-operations-8/pom.xml b/core-java-modules/core-java-string-operations-8/pom.xml
index 2495abccf8..a2f97a93d9 100644
--- a/core-java-modules/core-java-string-operations-8/pom.xml
+++ b/core-java-modules/core-java-string-operations-8/pom.xml
@@ -1,72 +1,34 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<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>core-java-string-operations-8</artifactId>
-    <name>core-java-string-operations-8</name>
-    <packaging>jar</packaging>
-
-    <parent>
-        <groupId>com.baeldung.core-java-modules</groupId>
-        <artifactId>core-java-modules</artifactId>
-        <version>0.0.1-SNAPSHOT</version>
-    </parent>
-
-    <dependencies>
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-lang3</artifactId>
-            <version>${apache.commons.lang3.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-text</artifactId>
-            <version>${commons-text.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.liquibase</groupId>
-            <artifactId>liquibase-core</artifactId>
-            <version>4.9.1</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter</artifactId>
-            <version>5.8.1</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.liquibase</groupId>
-            <artifactId>liquibase-core</artifactId>
-            <version>4.9.1</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <version>4.13.2</version>
-        </dependency>
-    </dependencies>
-
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <configuration>
-                    <source>${maven.compiler.source}</source>
-                    <target>${maven.compiler.target}</target>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
-
-    <properties>
-        <maven.compiler.source>11</maven.compiler.source>
-        <maven.compiler.target>11</maven.compiler.target>
-        <apache.commons.lang3.version>3.13.0</apache.commons.lang3.version>
-        <commons-text.version>1.10.0</commons-text.version>
-    </properties>
-
-</project>
\ No newline at end of file
+<?xml version="1.0" encoding="UTF-8"?>
+<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>core-java-string-operations-8</artifactId>
+    <name>core-java-string-operations-8</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>${maven.compiler.source}</source>
+                    <target>${maven.compiler.target}</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
+    </properties>
+
+</project>
diff --git a/core-java-modules/core-java-string-operations-8/src/test/java/com/baeldung/countupperandlowercasechars/CountUpperAndLowercaseCharsUnitTest.java b/core-java-modules/core-java-string-operations-8/src/test/java/com/baeldung/countupperandlowercasechars/CountUpperAndLowercaseCharsUnitTest.java
new file mode 100644
index 0000000000..cfef8d53ad
--- /dev/null
+++ b/core-java-modules/core-java-string-operations-8/src/test/java/com/baeldung/countupperandlowercasechars/CountUpperAndLowercaseCharsUnitTest.java
@@ -0,0 +1,85 @@
+package com.baeldung.countupperandlowercasechars;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class CountUpperAndLowercaseCharsUnitTest {
+    private static final String MY_STRING = "Hi, Welcome to Baeldung! Let's count letters!";
+    private static final LetterCount EXPECTED = new LetterCount(4, 31);
+
+    @Test
+    void whenIteratingCharArrayCompareAndCount_thenGetExpectedResult() {
+        int upperCnt = 0;
+        int lowerCnt = 0;
+        for (char c : MY_STRING.toCharArray()) {
+            if (c >= 'A' && c <= 'Z') {
+                upperCnt++;
+            }
+            if (c >= 'a' && c <= 'z') {
+                lowerCnt++;
+            }
+        }
+        LetterCount result = new LetterCount(upperCnt, lowerCnt);
+        assertEquals(EXPECTED, result);
+    }
+
+    @Test
+    void whenUsingCharacterIsLowerOrUpperCase_thenGetExpectedResult() {
+        int upperCnt = 0;
+        int lowerCnt = 0;
+        for (char c : MY_STRING.toCharArray()) {
+            if (Character.isUpperCase(c)) {
+                upperCnt++;
+            }
+            if (Character.isLowerCase(c)) {
+                lowerCnt++;
+            }
+        }
+        LetterCount result = new LetterCount(upperCnt, lowerCnt);
+        assertEquals(EXPECTED, result);
+    }
+
+    @Test
+    void whenUsingStreamFilterAndCount_thenGetExpectedResult() {
+        LetterCount result = new LetterCount(
+            (int) MY_STRING.chars().filter(Character::isUpperCase).count(),
+            (int) MY_STRING.chars().filter(Character::isLowerCase).count()
+        );
+        assertEquals(EXPECTED, result);
+    }
+}
+
+class LetterCount {
+    private int uppercaseCnt;
+    private int lowercaseCnt;
+
+    public LetterCount(int uppercaseCnt, int lowercaseCnt) {
+        this.uppercaseCnt = uppercaseCnt;
+        this.lowercaseCnt = lowercaseCnt;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (!(o instanceof LetterCount)) {
+            return false;
+        }
+
+        LetterCount that = (LetterCount) o;
+
+        if (uppercaseCnt != that.uppercaseCnt) {
+            return false;
+        }
+        return lowercaseCnt == that.lowercaseCnt;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = uppercaseCnt;
+        result = 31 * result + lowercaseCnt;
+        return result;
+    }
+}
\ No newline at end of file