[abs-int-diff] Return Absolute Difference Between Two Integers in Java (#13379)

core-java-modules/core-java-numbers-5/src/test/java/com/baeldung/absintdiff/AbsoluteDifferenceOfTwoIntUnitTest.java

@@ -0,0 +1,58 @@
+package com.baeldung.absintdiff;
+
+import static com.baeldung.absintdiff.IntDiffUtil.absDiff;
+import static com.baeldung.absintdiff.IntDiffUtil.absDiff2;
+import static com.baeldung.absintdiff.IntDiffUtil.absDiffAsLong;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+
+class IntDiffUtil {
+    static int absDiff(int num1, int num2) {
+        int result = Math.abs(num1 - num2);
+        System.out.println("Absolute diff: " + result);
+        return result;
+    }
+
+    static int absDiff2(int num1, int num2) {
+        return Math.abs(Math.subtractExact(num1, num2));
+    }
+
+    static long absDiffAsLong(int num1, int num2) {
+        return Math.abs((long) num1 - num2);
+    }
+}
+
+public class AbsoluteDifferenceOfTwoIntUnitTest {
+
+    @Test
+    void givenTwoIntegers_whenCallingAbsDiff_shouldGetExpectedResult() {
+        int diff1 = absDiff(100, -200);
+        assertEquals(300, diff1);
+
+        int diff2 = absDiff(100, 200);
+        assertEquals(100, diff2);
+
+        //integer overflow!  output: Absolute diff: 2147483449
+        //absDiff(Integer.MAX_VALUE, -200);
+    }
+
+    @Test
+    void givenTwoIntegers_whenCallingAbsDiff2_shouldThrowException() {
+        int diff1 = absDiff2(100, -200);
+        assertEquals(300, diff1);
+
+        int diff2 = absDiff2(100, 200);
+        assertEquals(100, diff2);
+
+        //overflow -> exception
+        assertThrows(ArithmeticException.class, () -> absDiff2(Integer.MAX_VALUE, -200));
+    }
+
+    @Test
+    void givenTwoIntegers_whenCallingAbsDiffAsLong_shouldThrowException() {
+        long diff = absDiffAsLong(Integer.MAX_VALUE, -200);
+        assertEquals(Integer.MAX_VALUE + 200L, diff);
+    }
+}