Swap two letters in a string

Question

I want to swap two letters in a string. For example, if input is W and H then all the occurrences of W in string should be replaced by H and all the occurrences of H should be replaced by W. String WelloHorld will become HelloWorld.

I know how to replace single char:

str = str.replace('W', 'H');

But I am not able to figure out how to swap characters.

Answer 1

public String getSwappedString(String s)
{
char ac[] = s.toCharArray();
for(int i = 0; i < s.length(); i++)
{
   if(ac[i] == 'H')
     ac[i]='W';
   else if(ac[i] == 'W')
     ac[i] = 'H'; 
}

s = new String(ac);
return s;
}