diff --git a/core-java-modules/core-java-numbers-conversions/src/test/java/com/baeldung/negate/NegateIntUnitTest.java b/core-java-modules/core-java-numbers-conversions/src/test/java/com/baeldung/negate/NegateIntUnitTest.java new file mode 100644 index 0000000000..444f4931d3 --- /dev/null +++ b/core-java-modules/core-java-numbers-conversions/src/test/java/com/baeldung/negate/NegateIntUnitTest.java @@ -0,0 +1,69 @@ +package com.baeldung.negate; + +import org.junit.jupiter.api.Test; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import static org.junit.jupiter.api.Assertions.*; + +public class NegateIntUnitTest { + + private static final Logger LOG = LoggerFactory.getLogger(NegateIntUnitTest.class); + + @Test + void whenUsingUnaryMinusOperator_thenGetExpectedResult() { + int x = 42; + assertEquals(-42, -x); + + int z = 0; + assertEquals(0, -z); + + int n = -42; + assertEquals(42, -n); + } + + @Test + void whenUsingBitwiseComplementOperator_thenGetExpectedResult() { + int x = 42; + assertEquals(-42, ~x + 1); + + int z = 0; + assertEquals(0, ~z + 1); + + int n = -42; + assertEquals(42, ~n + 1); + } + + @Test + void givenIntMinValue_whenUsingUnaryMinusOperator_thenCannotGetExpectedResult() { + int min = Integer.MIN_VALUE; + LOG.info("The value of '-min' is: " + -min); + + assertTrue((-min) < 0); + } + + @Test + void givenIntMinValue_whenUsingBitwiseComplementOperator_thenCannotGetExpectedResult() { + int min = Integer.MIN_VALUE; + int result = ~min + 1; + LOG.info("The value of '~min + 1' is: " + result); + + assertTrue(result < 0); + } + + + @Test + void whenUsingUnaryMinusOperatorWithMinInt_thenGetExpectedResult() { + int x = 42; + assertEquals(-42, Math.negateExact(x)); + + int z = 0; + assertEquals(0, Math.negateExact(z)); + + int n = -42; + assertEquals(42, Math.negateExact(n)); + + int min = Integer.MIN_VALUE; + assertThrowsExactly(ArithmeticException.class, () -> Math.negateExact(min)); + } +} \ No newline at end of file