Reverse a string in java code example
Example 1: reverse a string in java
Solution 1
public static String StrReverse(String str) {
String reverse="";
for(int i=str.length()-1; i >= 0; i--)
reverse += str.toCharArray()[i];
return reverse;
}
Solution 2 (using string buffer)
public static String Reverse(String str) {
return new StringBuffer(str).reverse().toString());
}
Example 2: Reverse a string in java
// reverse a string using character array
class ReverseUsingCharacterArray
{
public static void main(String[] args)
{
String str = "HelloWorldJava";
char[] ch = str.toCharArray();
for(int a = ch.length - 1; a >= 0; a--)
System.out.print(ch[a]);
}
}
Example 3: Reverse a string in java
// reverse a string using reverse() method of StringBuilder class
class ReverseUsingReverseMethod
{
public static void main(String[] args)
{
String str = "Hello world Java";
StringBuilder sb = new StringBuilder();
// append string to StringBuilder
sb.append(str);
sb = sb.reverse();
// printing reversed String
System.out.println(sb);
}
}
Example 4: reverse a string in java
Solution 1
public static String StrReverse(String str) {
String reverse="";
for(int i=str.length()-1; i >= 0; i--)
reverse += str.toCharArray()[i];
return reverse;
}
Solution 2 (using string buffer)
public static String Reverse(String str) {
return new StringBuffer(str).reverse().toString());
}
Example 5: Reverse a string in java
// reverse a string using toCharArray() method
class ReverseUsingToCharArrayMethod
{
public static void main(String[] args)
{
String str = "Hello World Java";
char[] chTemp = str.toCharArray();
int left, right = 0;
right = chTemp.length - 1;
for(left = 0; left < right ; left++, right--)
{
// swap values
char temp = chTemp[left];
chTemp[left] = chTemp[right];
chTemp[right]=temp;
}
for(char c : chTemp)
System.out.print(c);
System.out.println();
}
}
Example 6: Reverse a string in java
// reverse a string using ByteArray
class ReverseStringByteArray
{
public static void main(String[] args)
{
String input = "HelloWorld";
// getBytes() method to convert string into bytes[].
byte[] strByteArray = input.getBytes();
byte[] output = new byte[strByteArray.length];
// store output in reverse order
for(int a = 0; a < strByteArray.length; a++)
output[a] = strByteArray[strByteArray.length - a - 1];
System.out.println(new String(output));
}
}
Example 7: reverse a string in java
public class Main {
public static void main(String[] args) {
// Write a Java program to reverse a string.
Scanner input = new Scanner(System.in);
System.out.println("Enter the String:");
char[] letters = input.nextLine().toCharArray();
System.out.println(" Reverse String");
for(int i = letters.length -1; i >= 0; i--){
System.out.print(letters[i]);
}
}
}
Example 8: reverse a string in java
As we know that String is immutable. String class do not have reverse() method.
Example 9: reverse a string in java
// Not the best way i know but i wanted to challenge myself to do it this way so :)
public static String reverse(String str) {
char[] oldCharArray = str.toCharArray();
char[] newCharArray= new char[oldCharArray.length];
int currentChar = oldCharArray.length-1;
for (char c : oldCharArray) {
newCharArray[currentChar] = c;
currentChar--;
}
return new String(newCharArray);
}