Reverse a String in Java

 Reverse a String in Java

Hello and Welcome to The World of Computer Science and Technology

www.TechWithCode.com

Today we will learn about how to write a Java Program to Reverse a String in Java. Before moving forward, we must have knowledge about what is String Java?

What is String in Java?

The char type represents only one character. To represent a string of characters, use the data type called String. For example, the following code declares a message to be a string with the value "Welcome to TechWithCode".

String message = "Welcome to TechWithCode";

The string is a predefined class in the Java library, just like the classes System and Scanner.

The String type is not a primitive type. It is known as a reference type. Any Java class can be used as a reference type for a variable

The reverse of a String:

It refers that shifting the character of a string from left to right or vice-versa

Java Programm of Reverse of String:

There can be many ways to write a program to reverse a string in java but here we will see total four ways to write a java program to reverse a string.


1. Reverse a String in Java using CharAt Method

Problem Statement⤵️

Write a Java program to Reverse a String using CharAt Method.

Source code⤵️


import java.util.*;
public class StringReverse{
public static void main(String args[]) {
String inpt, rev="";
Scanner in=new Scanner(System.in);
System.out.println("Enter the string");
inpt=in.nextLine();
int length=inpt.length();
for(int i=length-1;i>=0;i--)
  rev=rev+inpt.charAt(i);
System.out.println("Reversed string: "+rev);
}
}


output⤵️


Enter the string
HELLO TECHWITHCODE
Reversed string: EDOCHTIWHCET OLLEH

2. Reverse a String in Java using String Builder / String Buffer Class

Problem Statement⤵️

Write a Java program to Reverse a String using String Builder / String Buffer Class.

Source code⤵️


import java.util.*; 
public class StringRev{
// Function to reverse a string in Java using StringBuilder
public static String rev(String s){
return new StringBuilder(s).reverse().toString();
}
public static void main(String[] args){
String s= "Welcome to TECHWITHCODE";
s= rev(s);
System.out.println("Result after reversing a string is : "+s);
}
}

output⤵️


Result after reversing a string is : ODOCHTIWHCET ot emocleW

3. String Reverse in java using Recursion

Problem Statement⤵️

Write a Java program to String Reverse using Recursion

Source code⤵️


import java.util.*;
public class StringRecursion{
String rev(String str) {
if(str.length() == 0)
return " ";
return str.charAt(str.length()-1) + rev(str.substring(0,str.length()-1)); }
public static void main(String[ ] args) {
StringRecursion r=new StringRecursion();
Scanner sc=new Scanner(System.in);
System.out.print("Enter the string : ");
String s=sc.nextLine();
System.out.println("Reversed String: "+r.rev(s)); }
}

output⤵️


Enter the string : TechWithCode is best CSE site
Reversed String: etis ESC si edoChtiWhceT

4. Reversing a String in java using Reverse Iteration

Problem Statement⤵️

Write a Java program to Reverse a String using Reverse Iteration.

Source code⤵️


import java.util.*;
public class StringRev{
// Function to reverse a string in Java 
public static String reverseString(String s){
//Converting the string into a character array
char c[]=s.toCharArray();
String reverse="";
//For loop to reverse a string
for(int i=c.length-1;i>=0;i--){
reverse+=c[i];
}
return reverse;
}
 
public static void main(String[] args) {
System.out.println(reverseString("Hi All"));
System.out.println(reverseString("Welcome to TechWithcode"));
}
}

output⤵️


llA iH
edoChtiWhceT ot emocleW





1 comment:

  1. Your blog contains lots of valuable data about website design seattle. It is a factual and beneficial article for us. Thankful to you for sharing an article like this.

    ReplyDelete

Do not add any link in the comments.
For backlink, contact us.

Powered by Blogger.