BAEL-6714: Convert Char Array to Int Array in Java (#14875)

core-java-modules/core-java-arrays-convert/src/main/java/com/baeldung/array/conversions/CharArrayToIntArrayUtils.java

@@ -0,0 +1,67 @@
+package com.baeldung.array.conversions;
+
+import java.util.Arrays;
+
+public class CharArrayToIntArrayUtils {
+
+    static int[] usingGetNumericValueMethod(char[] chars) {
+        if (chars == null) {
+            return null;
+        }
+
+        int[] ints = new int[chars.length];
+        for (int i = 0; i < chars.length; i++) {
+            ints[i] = Character.getNumericValue(chars[i]);
+        }
+
+        return ints;
+    }
+
+    static int[] usingDigitMethod(char[] chars) {
+        if (chars == null) {
+            return null;
+        }
+
+        int[] ints = new int[chars.length];
+        for (int i = 0; i < chars.length; i++) {
+            ints[i] = Character.digit(chars[i], 10);
+        }
+
+        return ints;
+    }
+
+    static int[] usingStreamApiMethod(char[] chars) {
+        if (chars == null) {
+            return null;
+        }
+
+        return new String(chars).chars()
+          .map(c -> c - 48)
+          .toArray();
+    }
+
+    static int[] usingParseIntMethod(char[] chars) {
+        if (chars == null) {
+            return null;
+        }
+
+        int[] ints = new int[chars.length];
+        for (int i = 0; i < chars.length; i++) {
+            ints[i] = Integer.parseInt(String.valueOf(chars[i]));
+        }
+
+        return ints;
+    }
+
+    static int[] usingArraysSetAllMethod(char[] chars) {
+        if (chars == null) {
+            return null;
+        }
+
+        int[] ints = new int[chars.length];
+        Arrays.setAll(ints, i -> Character.getNumericValue(chars[i]));
+
+        return ints;
+    }
+
+}

core-java-modules/core-java-arrays-convert/src/test/java/com/baeldung/array/conversions/CharArrayToIntArrayUtilsUnitTest.java

@@ -0,0 +1,54 @@
+package com.baeldung.array.conversions;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+
+import org.junit.jupiter.api.Test;
+
+class CharArrayToIntArrayUtilsUnitTest {
+
+    @Test
+    void givenCharArray_whenUsingGetNumericValueMethod_shouldGetIntArray() {
+        int[] expected = { 2, 3, 4, 5 };
+        char[] chars = { '2', '3', '4', '5' };
+        int[] result = CharArrayToIntArrayUtils.usingGetNumericValueMethod(chars);
+
+        assertArrayEquals(expected, result);
+    }
+
+    @Test
+    void givenCharArray_whenUsingDigitMethod_shouldGetIntArray() {
+        int[] expected = { 1, 2, 3, 6 };
+        char[] chars = { '1', '2', '3', '6' };
+        int[] result = CharArrayToIntArrayUtils.usingDigitMethod(chars);
+
+        assertArrayEquals(expected, result);
+    }
+
+    @Test
+    void givenCharArray_whenUsingStreamApi_shouldGetIntArray() {
+        int[] expected = { 9, 8, 7, 6 };
+        char[] chars = { '9', '8', '7', '6' };
+        int[] result = CharArrayToIntArrayUtils.usingStreamApiMethod(chars);
+
+        assertArrayEquals(expected, result);
+    }
+
+    @Test
+    void givenCharArray_whenUsingParseIntMethod_shouldGetIntArray() {
+        int[] expected = { 9, 8, 7, 6 };
+        char[] chars = { '9', '8', '7', '6' };
+        int[] result = CharArrayToIntArrayUtils.usingParseIntMethod(chars);
+
+        assertArrayEquals(expected, result);
+    }
+
+    @Test
+    void givenCharArray_whenUsingArraysSetAllMethod_shouldGetIntArray() {
+        int[] expected = { 4, 9, 2, 3 };
+        char[] chars = { '4', '9', '2', '3' };
+        int[] result = CharArrayToIntArrayUtils.usingArraysSetAllMethod(chars);
+
+        assertArrayEquals(expected, result);
+    }
+
+}