[int-zero-or-null] Check if an Integer Value is null or Zero in Java (#13332)

core-java-modules/core-java-numbers-5/src/main/java/com/baeldung/IntegerNullOrZero.java

@@ -0,0 +1,26 @@
+package com.baeldung;
+
+import java.util.Optional;
+import org.apache.commons.lang3.ObjectUtils;
+
+public class IntegerNullOrZero {
+    private IntegerNullOrZero() {
+        throw new RuntimeException("This class cannot be instantiated.");
+    }
+
+    public static boolean usingStandardWay(Integer num) {
+        return num == null || num == 0;
+    }
+
+    public static boolean usingTernaryOperator(Integer num) {
+        return 0 == (num == null ? 0 : num);
+    }
+
+    public static boolean usingOptional(Integer num) {
+        return Optional.ofNullable(num).orElse(0) == 0;
+    }
+
+    public static boolean usingObjectUtils(Integer num) {
+        return ObjectUtils.defaultIfNull(num, 0) == 0;
+    }
+}

core-java-modules/core-java-numbers-5/src/test/java/com/baeldung/intnullorzero/IntegerNullOrZeroUnitTest.java

@@ -0,0 +1,69 @@
+package com.baeldung.intnullorzero;
+
+import static com.baeldung.IntegerNullOrZero.usingObjectUtils;
+import static com.baeldung.IntegerNullOrZero.usingOptional;
+import static com.baeldung.IntegerNullOrZero.usingStandardWay;
+import static com.baeldung.IntegerNullOrZero.usingTernaryOperator;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+public class IntegerNullOrZeroUnitTest {
+
+    @Test
+    void givenInts_whenUsingStandardWay_thenGetExpectedResult() {
+        int n0 = 0;
+        boolean result0 = usingStandardWay(n0);
+        assertTrue(result0);
+
+        boolean resultNull = usingStandardWay(null);
+        assertTrue(resultNull);
+
+        int n42 = 42;
+        boolean result42 = usingStandardWay(n42);
+        assertFalse(result42);
+    }
+
+    @Test
+    void givenInts_whenUsingTernaryOperator_thenGetExpectedResult() {
+        int n0 = 0;
+        boolean result0 = usingTernaryOperator(n0);
+        assertTrue(result0);
+
+        boolean resultNull = usingTernaryOperator(null);
+        assertTrue(resultNull);
+
+        int n42 = 42;
+        boolean result42 = usingTernaryOperator(n42);
+        assertFalse(result42);
+    }
+
+    @Test
+    void givenInts_whenUsingOptional_thenGetExpectedResult() {
+        int n0 = 0;
+        boolean result0 = usingOptional(n0);
+        assertTrue(result0);
+
+        boolean resultNull = usingOptional(null);
+        assertTrue(resultNull);
+
+        int n42 = 42;
+        boolean result42 = usingOptional(n42);
+        assertFalse(result42);
+    }
+
+    @Test
+    void givenInts_whenUsingObjectUtils_thenGetExpectedResult() {
+        int n0 = 0;
+        boolean result0 = usingObjectUtils(n0);
+        assertTrue(result0);
+
+        boolean resultNull = usingObjectUtils(null);
+        assertTrue(resultNull);
+
+        int n42 = 42;
+        boolean result42 = usingObjectUtils(n42);
+        assertFalse(result42);
+    }
+}