[slicingArrays] Slicing Arrays in Java (#12957)

core-java-modules/core-java-arrays-operations-advanced/src/test/java/com/baeldung/arrayslicing/SlicingArrayUnitTest.java

@@ -0,0 +1,43 @@
+package com.baeldung.arrayslicing;
+
+import org.apache.commons.lang3.ArrayUtils;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+
+public class SlicingArrayUnitTest {
+    private static final String[] LANGUAGES = new String[] { "Python", "Java", "Kotlin", "Scala", "Ruby", "Go", "Rust" };
+    private static final String[] JVM_LANGUAGES = new String[] { "Java", "Kotlin", "Scala" };
+
+    @Test
+    void givenAnArray_whenSlicingUsingStream_shouldGetExpectedResult() {
+        String[] result = Arrays.stream(LANGUAGES, 1, 4).toArray(String[]::new);
+        assertArrayEquals(JVM_LANGUAGES, result);
+    }
+
+    @Test
+    void givenAnArray_whenSlicingUsingArraysCopyOfRange_shouldGetExpectedResult() {
+        String[] result = Arrays.copyOfRange(LANGUAGES, 1, 4);
+        assertArrayEquals(JVM_LANGUAGES, result);
+    }
+
+
+    @Test
+    void givenAnArray_whenSlicingUsingSystemArraycopy_shouldGetExpectedResult() {
+        String[] result = new String[3];
+        System.arraycopy(LANGUAGES, 1, result, 0, 3);
+        assertArrayEquals(JVM_LANGUAGES, result);
+
+        String[] result2 = new String[] { "value one", "value two", "value three", "value four", "value five", "value six", "value seven" };
+        System.arraycopy(LANGUAGES, 1, result2, 2, 3);
+        assertArrayEquals(new String[] { "value one", "value two", "Java", "Kotlin", "Scala", "value six", "value seven" }, result2);
+    }
+
+    @Test
+    void givenAnArray_whenSlicingUsingArrayUtils_shouldGetExpectedResult() {
+        String[] result = ArrayUtils.subarray(LANGUAGES, 1, 4);
+        assertArrayEquals(JVM_LANGUAGES, result);
+    }
+}