Reverse - Learn Java by Examples

Below is an example code that reverse a string. In this example we use StringBuffer.reverse() method to reverse a string. In Java 1.5, a new class called StringBuilder also has a reverse() method that do just the same, one of the difference is StringBuffer class is synchronized while StringBuilder class is not.

And here is the string reverse in the StringBuffer way.

package org.kodejava.lang;

public class StringReverseExample {
    public static void main(String[] args) {
        // The normal sentence that is going to be reversed.
        String words =
                "Morning of The World - The Last Paradise on Earth";

        // To reverse the string we can use the reverse() method in
        // the StringBuffer class. The reverse() method returns a
        // StringBuffer so we need to call the toString() method to
        // get a string object.
        String reverse = new StringBuffer(words).reverse().toString();

        // Print the normal string
        System.out.println("Normal : " + words);
        // Print the string in reversed order
        System.out.println("Reverse: " + reverse);
    }
}

Beside using this simple method you can try to reverse a string by converting it to character array and then reverse the array order.

And below is the result of the code snippet above.

Normal : Morning of The World - The Last Paradise on Earth
Reverse: htraE no esidaraP tsaL ehT - dlroW ehT fo gninroM

package org.kodejava.commons.lang; import org.apache.commons.lang3.StringUtils; public class StringReverseDemo { public static void main(String[] args) { // We have an original string here that we'll need to reverse. String words = "The quick brown fox jumps over the lazy dog"; // Using StringUtils.reverse we can reverse the string letter by letter. String reversed = StringUtils.reverse(words); // Now we want to reverse per word, we can use // StringUtils.reverseDelimited() method to do this. String delimitedReverse = StringUtils.reverseDelimited(words, ' '); // Print out the result System.out.println("Original: " + words); System.out.println("Reversed: " + reversed); System.out.println("Delimited Reverse: " + delimitedReverse); } }

Tag Archives: Reverse

How do I reverse a string?

How do I reverse a string, words or sentences?