BAEL-1305: A Simple Guide to Java Loops. (#3133)

core-java/src/main/java/com/baeldung/loops/LoopsInJava.java

@@ -0,0 +1,43 @@
+package com.baeldung.loops;
+
+public class LoopsInJava {
+
+    public int[] simple_for_loop() {
+        int[] arr = new int[5];
+        for (int i = 0; i < 5; i++) {
+            arr[i] = i;
+            System.out.println("Simple for loop: i - " + i);
+        }
+        return arr;
+    }
+
+    public int[] enhanced_for_each_loop() {
+        int[] intArr = { 0, 1, 2, 3, 4 };
+        int[] arr = new int[5];
+        for (int num : intArr) {
+            arr[num] = num;
+            System.out.println("Enhanced for-each loop: i - " + num);
+        }
+        return arr;
+    }
+
+    public int[] while_loop() {
+        int i = 0;
+        int[] arr = new int[5];
+        while (i < 5) {
+            arr[i] = i;
+            System.out.println("While loop: i - " + i++);
+        }
+        return arr;
+    }
+
+    public int[] do_while_loop() {
+        int i = 0;
+        int[] arr = new int[5];
+        do {
+            arr[i] = i;
+            System.out.println("Do-While loop: i - " + i++);
+        } while (i < 5);
+        return arr;
+    }
+}

core-java/src/test/java/com/baeldung/loops/WhenUsingLoops.java

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+package com.baeldung.loops;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class WhenUsingLoops {
+
+    private LoopsInJava loops = new LoopsInJava();
+
+    @Test
+    public void shouldRunForLoop() {
+        int[] expected = { 0, 1, 2, 3, 4 };
+        int[] actual = loops.simple_for_loop();
+        Assert.assertArrayEquals(expected, actual);
+    }
+
+    @Test
+    public void shouldRunEnhancedForeachLoop() {
+        int[] expected = { 0, 1, 2, 3, 4 };
+        int[] actual = loops.enhanced_for_each_loop();
+        Assert.assertArrayEquals(expected, actual);
+    }
+
+    @Test
+    public void shouldRunWhileLoop() {
+        int[] expected = { 0, 1, 2, 3, 4 };
+        int[] actual = loops.while_loop();
+        Assert.assertArrayEquals(expected, actual);
+    }
+
+    @Test
+    public void shouldRunDoWhileLoop() {
+        int[] expected = { 0, 1, 2, 3, 4 };
+        int[] actual = loops.do_while_loop();
+        Assert.assertArrayEquals(expected, actual);
+    }
+}