Php Question

[noexp]

I have a doubt,
I wonder how to turn this to php.

private static void byteEncrypt(byte data[]){
for(int i = 0 ; i < BYTE.LENGHT ; i++){
if(i % 2 == 0){
data ^= XOR0;
}else{
data ^= XOR1;
}
}
}

thx