Write a method to replace all spaces with %20 in a String.(Note-Perform in place operation only.)

public void replaceSpaces(Char[] str, int length)

{

  int spaceCount=0;

  int newLength,i;

   for(i=0;i<lenght;i++)

   {

     if(str[i] == ' ')

      {

         spaceCount++;

      }

   }

  newLenght =newLength + spaceCount *2;

 str[newLength] = '\0' ;

 for( i=length -1; i>=0,i--)

 {

   if(str[i] == ' ')

   {

     str[newLength -1] = '0';

    str[newLength -2] = '2';

    str[newLength -3] = '%';

    newLength =newLength - 3 ;

   }

  else

  {

     str[newLength -1] = str[i] ;

     newLength =newLength - 1;

  }

 }

}

 Note: i have implemented this problem using character arrays because java string are immutable.if you will use string directly.this would require a new copy of the string but it would allow us  to implement this in just one pass.