Why can't variables be declared in an if statement?

Question

The following Java code does not compile.

int a = 0;

if(a == 1) {
    int b = 0;
}

if(a == 1) {
    b = 1;
}

Why? There can be no code pa

Answer 1

Because when b goes out of scope in the first if (a == 1) then it will be removed and no longer exists on the stack and therefore can not be used in the next if statement.