[strArrayToIntArray] convert str array to int array (#13217)

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

@@ -0,0 +1,63 @@
+package com.baeldung.array.conversions;
+
+import org.junit.jupiter.api.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+
+
+public class StringArrayToIntArrayUnitTest {
+    private final String[] stringArray = new String[] { "1", "2", "3", "4", "5", "6", "42" };
+    private final int[] expected = new int[] { 1, 2, 3, 4, 5, 6, 42 };
+
+    private final String[] stringArrayWithInvalidNum = new String[] { "1", "2", "hello", "4", "world", "6", "42" };
+    private final int[] expectedWithInvalidInput = new int[] { 1, 2, Integer.MIN_VALUE, 4, Integer.MIN_VALUE, 6, 42 };
+
+    private final Logger logger = LoggerFactory.getLogger(this.getClass());
+
+    @Test
+    void givenStringArray_whenUseStreamApi_shouldGetExpectedIntArray() {
+        int[] result = Arrays.stream(stringArray).mapToInt(Integer::parseInt).toArray();
+        assertArrayEquals(expected, result);
+    }
+
+    @Test
+    void givenStringArrayWithInvalidNum_whenUseStreamApi_shouldGetExpectedIntArray() {
+        int[] result = Arrays.stream(stringArrayWithInvalidNum).mapToInt(s -> {
+            try {
+                return Integer.parseInt(s);
+            } catch (NumberFormatException ex) {
+                logger.warn("Invalid number format detected: {}, use Int.MinValue as the fallback", s);
+                return Integer.MIN_VALUE;
+            }
+        }).toArray();
+        assertArrayEquals(expectedWithInvalidInput, result);
+    }
+
+    @Test
+    void givenStringArray_whenConvertInLoop_shouldGetExpectedIntArray() {
+        int[] result = new int[stringArray.length];
+        for (int i = 0; i < stringArray.length; i++) {
+            result[i] = Integer.parseInt(stringArray[i]);
+        }
+        assertArrayEquals(expected, result);
+    }
+
+    @Test
+    void givenStringArrayWithInvalidNum_whenConvertInLoop_shouldGetExpectedIntArray() {
+        int[] result = new int[stringArrayWithInvalidNum.length];
+        for (int i = 0; i < stringArrayWithInvalidNum.length; i++) {
+            try {
+                result[i] = Integer.parseInt(stringArrayWithInvalidNum[i]);
+            } catch (NumberFormatException exception) {
+                logger.warn("Invalid number format detected: [{}], use Int.MinValue as the fallback", stringArrayWithInvalidNum[i]);
+                result[i] = Integer.MIN_VALUE;
+            }
+        }
+
+        assertArrayEquals(expectedWithInvalidInput, result);
+    }
+}