Question

it has been 8 years since I last programmed, and then it was just basics for a networking degree. I am writing a basic program to start my way back into java programming. the program is dealing with binary numbers stored as strings.

e.g. 01101110010

I have got everything else working, but now I want to swap all “1” for “0” and all “0” for “1”

to get 10010001101

The problem is the only way I know to swap chars is to create a new string with the chars replaced but I can only do one char at a time and then I just end up with a string of all 1s or 0s

so I thought about using a char array and trying to swap each char in the array but I have no idea how to go about this.

Answer 1

String str = "0101010101110";
char[] cs = str.toCharArray();
for (int i = 0; i < cs.length; i++)
{
    if (cs[i] == '1')
        cs[i] = '0';
    else if (cs[i] == '0')
        cs[i] = '1';
}
str = new String(cs);