Create ReverseString.java

Author: jfullstackdev

src/ReverseString.java

@@ -0,0 +1,22 @@
+public class ReverseString {
+
+	public static void main(String[] args) {
+
+		String str = "789";
+		System.out.println(reverseString(str));
+	}
+
+	public static String reverseString(String in) {
+		if (in == null)
+			throw new IllegalArgumentException("input null");
+
+		StringBuilder out = new StringBuilder();
+
+		char[] chars = in.toCharArray();
+
+		for (int i = chars.length - 1; i >= 0; i--)
+			out.append(chars[i]);
+
+		return out.toString();
+	}
+}