Answers for "str rev function in string in java"

java reverse a string

// Library approach
public static String solution(String str) {
	// StringBuilder is not thread-safe, use StringBuffer
	return new StringBuffer(str).reverse().toString();
}

// DIY approach
public static String solution(String str) {
	char[] chars = str.toCharArray();
	for(int i = 0, j = str.length() - 1; i < j; i++, j--) {
		char ch = chars[i];
		chars[i] = chars[j];
		chars[j] = ch;
	}
	return new String(chars);
}

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();
   }
}