- Java Basic Programs
- Java Programming Examples
- Java Print Hello World
- Java Get Input from User
- Java Print Integer
- Java Add two Numbers
- Java Check Even or Odd
- Java Check Prime or Not
- Java Check Alphabet or Not
- Java Check Vowel or Not
- Check Reverse equal Original
- Java Fahrenheit to Celsius
- Java Celsius to Fahrenheit
- Java Perfect Number Program
- Java Find Quotient Remainder
- Java Days to Seconds
- Java Count Digits in Number
- Java Binary Number Addition
- Java Discount Program
- Java Compute Courier Charge
- Java Find Telephone Bill
- Java Print ASCII Values
- Java Check Palindrome or Not
- Java Check Armstrong or Not
- Generate Armstrong Numbers
- Add two Numbers using Pointers
- Java Mathematical Programs
- Add Subtract Multiply & Divide
- Java Make Calculator
- Java Add Digits of Number
- Java Check Leap Year or Not
- Java Check Divisibility
- Java Find Simple Interest
- Java Find Compound Interest
- Java Print Fibonacci Series
- Java Find nCr nPr
- Calculate Average & Percentage
- Java Calculate Arithmetic Mean
- Java Calculate Student Grade
- Java Print Table of Number
- Java Print Prime Numbers
- Java Add n Numbers
- Java Interchange two Numbers
- Java Reverse Numbers
- Java Swap two Numbers
- Count Positive Negative & Zero
- Find Largest of two Numbers
- Find Largest of three Numbers
- Java Find Factorial of Number
- Java Find HCF & LCM
- Area & Perimeter of Square
- Area & Perimeter of Rectangle
- Area & Circumference of Circle
- Java Conversion Programs
- Java Decimal to Binary
- Java Decimal to Octal
- Java Decimal to Hexadecimal
- Java Binary to Decimal
- Java Binary to Octal
- Java Binary to Hexadecimal
- Java Octal to Decimal
- Java Octal to Binary
- Java Octal to Hexadecimal
- Java Hexadecimal to Decimal
- Java Hexadecimal to Binary
- Java Hexadecimal to Octal
- Java Pattern Programs
- Java Pattern of Stars
- Java Pattern of Alphabets
- Java Pattern of Numbers
- Java Pyramid of Stars
- Java Pyramid of Alphabets
- Java Pyramid of Numbers
- Java Print Diamond Pattern
- Java Print Floyd Triangle
- Java Print Pascal Triangle
- Java Array Programs
- One Dimensional Array Program
- Java Linear Search
- Java Binary Search
- Find Largest Element in Array
- Find Smallest Element in Array
- Java Reverse Array
- Insert Element in Array
- Delete Element from Array
- Java Merge two Array
- Java Bubble Sort
- Java Selection Sort
- Java Insertion Sort
- Java Find Common Elements
- Java Count Even/Odd Number
- Two Dimensional Array Program
- Java Add two Matrices
- Java Subtract two Matrices
- Java Transpose Matrix
- Multiply two Matrices
- Three Dimension Array Program
- Java String Programs
- Java Print String
- Find Length of String
- Java Compare two String
- Java Copy String
- Java Concatenate String
- Java Reverse String
- Delete Vowels from String
- Delete Words from Sentence
- Find Occurrence of a Character
- Java Find Occurrence of a Word
- Occurrence of Each Character
- Java Occurrence of Each Word
- Java Count Repeated Characters
- Java Count Repeated Words
- Java Capitalize Each Word
- Java Count Vowels/Consonants
- Java Extract Numbers
- Java Count Word in String
- Remove Spaces from String
- Java Sort a String
- Java Uppercase to Lowercase
- Java Lowercase to Uppercase
- Java Swap two Strings
- Java Check Anagram or Not
- Java Check Balance Parentheses
- Java Check Password Strength
- Java File Programs
- Java Read File
- Java Write to File
- Read & Display File Content
- Java Copy File
- Java Append Text to File
- Java Merge two File
- List files in Directory
- Java Delete File
- Java Miscellaneous Programs
- Generate Random Numbers
- Java Print Time & Date
- Java Get IP Address
- Java Shutdown Computer
- Java Programming Tutorial
- Java Tutorial
Java Program to Reverse a String
This article is created to cover, one of the famous program in Java, that is to reverse a string entered by user at run-time of the program. Here are the list of programs covered in this article:
- Reverse a String using for Loop
- Reverse a String using while Loop
- Reverse a String using reverse() method
- Reverse a String using character array
- Reverse a String, word-wise
Reverse a String in Java using for Loop
The question is, write a Java program to reverse a given string. The string must be received by user at run-time. The program given below is its answer:
import java.util.Scanner; public class fresherearth { public static void main(String[] args) { String str, strReverse=""; int len, i; char ch; Scanner s = new Scanner(System.in); System.out.print("Enter the String: "); str = s.nextLine(); len = str.length(); for(i=(len-1); i>=0; i--) { ch = str.charAt(i); strReverse = strReverse + ch; } System.out.println("\nReverse = " +strReverse); } }
The snapshot given below shows the sample run of above Java program on reversing of a given string, with user input fresherearth dot com as string to reverse:
The string gets reversed with preserving the position of white spaces.
Reverse a String in Java using while Loop
This program does the same job as of previous program, but created using while loop, instead of for.
import java.util.Scanner; public class fresherearth { public static void main(String[] args) { String str, strReverse=""; int len, i; char ch; Scanner s = new Scanner(System.in); System.out.print("Enter the String: "); str = s.nextLine(); len = str.length(); i = (len-1); while(i>=0) { ch = str.charAt(i); strReverse = strReverse + ch; i--; } System.out.println("\nReverse = " +strReverse); } }
You'll get the same output as of previous program. The above program can also be created in this way too:
import java.util.Scanner; public class fresherearth { public static void main(String[] args) { String strReverse=""; Scanner s = new Scanner(System.in); System.out.print("Enter the String: "); String str = s.nextLine(); int len = str.length(); int i = (len-1); while(i>=0) strReverse += str.charAt(i--); System.out.println("\nReverse = " +strReverse); } }
Still, you'll get the same output.
Reverse a String using StringBuilder and reverse() Function
This program uses StringBuilder class and its method named reverse() to reverse a string.
import java.util.Scanner; public class fresherearth { public static void main(String[] args) { Scanner s = new Scanner(System.in); System.out.print("Enter the String: "); String str = s.nextLine(); StringBuilder sb = new StringBuilder(str); sb.reverse(); String strReverse = sb.toString(); System.out.println("\nReverse = " +strReverse); } }
Reverse a String in Java using a Character Array
This program uses character array to reverse a string. The toCharArray() method converts a string into character array.
import java.util.Scanner; public class fresherearth { public static void main(String[] args) { String strReverse = ""; Scanner s = new Scanner(System.in); System.out.print("Enter the String: "); String str = s.nextLine(); char ch[] = str.toCharArray(); int len = ch.length; for(int i=(len-1); i>=0; i--) strReverse += ch[i]; System.out.println("\nReverse = " +strReverse); } }
Reverse a String Word Wise
This is the last program of this article. This program is little different from all the program given above. As this program reverse a string, but in word-wise manner.
import java.util.Scanner; public class fresherearth { public static void main(String[] args) { String word, wordReverse; int tot, i, len, j; char ch; Scanner s = new Scanner(System.in); System.out.print("Enter the String: "); String str = s.nextLine(); String words[] = str.split(" "); tot = words.length; System.out.print("\nWord Wise Reverse of String = "); for(i=0; i<tot; i++) { wordReverse = ""; word = words[i]; len = word.length(); for(j=(len-1); j>=0; j--) { ch = word.charAt(j); wordReverse = wordReverse + ch; } System.out.print(wordReverse+ " "); } } }
Here is its sample run with same user input as of first program's sample run:
In above program, if user inputs a string that contains more than one white spaces in between any two or more words, then the program will not work perfectly. Therefore let me modify the program, and create a new one. This program also stores the reverse of string, word wise, then prints the whole string at last.
import java.util.Scanner; public class fresherearth { public static void main(String[] args) { String strReverse = ""; String word, wordReverse; Scanner s = new Scanner(System.in); System.out.print("Enter the String: "); String str = s.nextLine(); String words[] = str.split("\\s+"); int tot = words.length; for(int i=0; i<tot; i++) { wordReverse = ""; word = words[i]; int len = word.length(); for(int j=(len-1); j>=0; j--) wordReverse += word.charAt(j); strReverse = strReverse + wordReverse + " "; } System.out.println("\nReverse (Word-wise) = " +strReverse); } }
Here is its sample run with user input Java is Robust
Same Program in Other Languages
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