How to reverse a String in Java?

ALSO CHECK: Algorithms and System Design Interview Questions

How to reverse a String is one of the common interview question. In Java, we can do this in a couple of ways:

• Reverse a String using CharAt Method
• String reverse using String Buffer/String Builder Approach
• Reverse a String using Reverse Iterative Approach
• String reverse using Recursion

GIT URL: How to reverse a String in Java

	public class StringReverse {
	//Reverse a String using CharAt Method
	public String reverStringCharAt(String str) {
	String reverseStr="";
	for(int i=str.length()-1;i>=0;i--)
	reverseStr=reverseStr+str.charAt(i);
	return reverseStr;
	}
	// Reverse a String using String Builder
	public String reverStringBuilder(String str) {
	return new StringBuilder(str)
	.reverse().toString();
	}
	// Reverse a String using String Buffer
	public String reverStringBuffer(String str) {
	return new StringBuffer(str)
	.reverse().toString();
	}
	//Reverse a String using Reverse Iteration
	public String reverStringItr(String str) {
	char c[]=str.toCharArray();
	String reverseStr="";
	//For loop to reverse a string
	for(int i=c.length-1;i>=0;i--)
	reverseStr+=c[i];
	return reverseStr;
	}
	//Reverse a String using Recursion
	public String reverStringRec(String str) {
	if(str.length() == 0)
	return " ";
	return str.charAt(str.length()-1) +
	reverStringRec(str.substring(0,str.length()-1));
	}
	}

view raw StringReverse.java hosted with ❤ by GitHub

Reverse each word in String
Recently I applied for a Senior Java Developer position in a small IT company in Mumbai. In the first round of interview they asked me solve a couple of puzzles and algorithms. One of the questions that was asked is to write a Java Program to reverse each word in String.

public String reverseEachWord(String str){
  //get all words in an array
  String words[]=str.split("\\s");  
  String reverseWord="";
  StringBuilder sb;
  
  for(String word:words){  
    sb=new StringBuilder(word);  
    sb.reverse();  
    reverseWord+=sb.toString()+" ";  
  }  
  return reverseWord.trim();
}
-K Himaanshu Shuklaa..