Swap Case

ardallie · ardallie · commit dfd840a59d4a · 2021-08-16T21:54:33.000+01:00
diff --git a/src/easy/SwapCase.java b/src/easy/SwapCase.java
@@ -0,0 +1,42 @@
+package easy;
+
+/**
+ * Have the function SwapCase(str) take the str parameter
+ * and swap the case of each character.
+ * For example: if str is "Hello World" the output should be hELLO wORLD.
+ * Let numbers and symbols stay the way they are.
+ */
+public class SwapCase {
+
+  /**
+   * Swap Case function.
+   *
+   * @param str input string
+   * @return the output string
+   */
+  private static String swapCase(String str) {
+    StringBuilder out = new StringBuilder();
+    char[] chars = str.toCharArray();
+    for (char c : chars) {
+      if (Character.isLowerCase(c)) {
+        out.append(Character.toUpperCase(c));
+      } else {
+        out.append(Character.toLowerCase(c));
+      }
+    }
+    return out.toString();
+  }
+
+  /**
+   * Entry point.
+   *
+   * @param args command line arguments
+   */
+  public static void main(String[] args) {
+    var result1 = swapCase("The Livin' Free EP");
+    System.out.println(result1);
+    var result2 = swapCase("Selected MP3");
+    System.out.println(result2);
+  }
+
+}
