In C++ you use == for comparison. The = is an assignment. It can be used in the condition of an if statement, but it’s going to evaluate to true unless the character is ‘ ’ (not ‘0’, as it is in your case):
if(fg == x[0])
{
…
}
Within if statement use ==. For Eg:
if (fg == x[0]) {
//………..
}
== compares, but = makes fg equal to x[0], and that’s why you get true every time.