invert a value of bit in digit (Java)-CodePudding

I want to invert a value of bit in digit. Function should invert value by number of bit, like this

public static void main(String[] args) {

    int res = flipBit(7,1);
}

public static int flipBit(int value, int bitIndex) {

    String bin = Integer.toBinaryString(value);
    char newChar = (char) (bin.charAt(bitIndex) ^ bin.charAt(bitIndex));
    
    //pseudo code
    bin[bitIndex] = newChar;    
    
    return Integer.parseInt(bin);
}

CodePudding user response：

Assuming that bitIndex is zero-based, it might be done using XOR operator like that (credits to @Iłya Bursov since he has pointed out it earlier in the comments):

public static int flipBit(int value, int bitIndex) {
    if (bitIndex < 0 || bitIndex > 31) {
        throw new IllegalArgumentException();
    }
    
    return value ^ 1 << bitIndex;
}

CodePudding user response：

How about:

String bin = Integer.toBinaryString( value );
char newChar = (char) (bin.charAt(bitIndex) ^ bin.charAt(bitIndex));

StringBuilder sb = new StringBuilder( bin );
sb.setCharAt( bitIndex, newChar );
return sb.toString();