Java reverse string program: This Java program reverses a string entered by a user. To create this article, 9 people, some anonymous, worked to edit and improve it over time. And then calls itself on the remainder of the string str. In this tutorial we will discuss how to reverse a string in java. Though its also a and you should practice it before going for any Java programming interview. Then, the character at index k in the new character sequence is equal to the character at index n-k-1 in the old character sequence.
Solution Following example shows how to reverse a String after taking it from command line argument. The user will input the string to be reversed. Swap the characters of the start index scanning with the last index scanning one by one. Based on words- import java. Set the left index equal to 0 and right index equal to the length of the string -1. Input : Alive is awesome Output: emosewa si evilA Input : Be in present Output : tneserp ni eB Read Also : Points to Keep in Mind Before attempting the Solution: 1.
In the second method , we will use the built in reverse method of the StringBuilder class ,. By looping through character array and appending it into empty String we can get reversed String in Java, as shown in the following example. Here is the method which reverses the string by calling itself recursively. Given a string Input a string and we have to reverse input string with and without using StringBuffer. Because the length of passed string is 1. . After that print out the characters of the reversed string by scanning from the first till the last index.
First, convert String to character array by using the built in Java String class method toCharArray. Convert the input string into the character array by using toCharArray built in method. Set the left index equal to 0 and right index equal to the length of the string -1. In , we have first used StringBuffer and StringBuilder to reverse contents of String and then we wrote our own logic to reverse String. And then we iterate that array in the reverse order.
In this section, we are going to reverse a given string. But sometimes you have a task to implement string reversal using , recursion or even reverse a string word by word. After that increase the left index by 1 left++ and decrease the right by 1 i. Prerequisite : Following are some interesting facts about String and StringBuffer classes : 1. This example also shows how to reverse words as well as reverse the order of the individual words of the String in Java.
ListIterator object is used to iterate over the list. » How to reverse a string in Java with and without using StringBuffer. This is my understanding but i know i am. ListIterator object is used to iterate over the list. So we need to convert the input string to StringBuilder , which is achieved by using the append method of the StringBuilder. There are many ways the reversal of a string can be done in Java.
Fortunately, it is quiet easy to make a method to do it. Java library provides class with reverse method which can be used to reverse String in Java. We will create the ListIterator object by using the listIterator method on the LinkedList object. This solution reverse the pair and will corrupt the characters. They may ask you to use recursion to write reverse String function instead of using for loop.
We use charAt method to extract characters from the input string and append them in reverse order to reverse the string. Since Collections class reverse method takes a list object , to reverse the list , we will pass the LinkedList object which is a type of list of characters. So here i am providing solutions for both. Java also has built in reverse method for the Collections class. In this program, there is an example in java where you will learn how to reverse a string with and without using StringBuffer.