How to reverse and output a string in Java?

You can reverse a string in Java using the reverse() method from the StringBuilder or StringBuffer class. Here is an example code:

public class StringReverseExample {
    public static void main(String[] args) {
        String str = "Hello World!";
        
        // 使用StringBuilder类
        StringBuilder sb = new StringBuilder(str);
        sb = sb.reverse();
        System.out.println(sb.toString());
        
        // 使用StringBuffer类
        StringBuffer sbf = new StringBuffer(str);
        sbf = sbf.reverse();
        System.out.println(sbf.toString());
    }
}

Output result:

!dlroW olleH
!dlroW olleH

In the example above, we first created a string “str”, then we used the StringBuilder and StringBuffer classes to reverse it, and finally converted the reversed string to a string type using the toString() method. Finally, we used the System.out.println() method to output the reversed string.