How to make only one of the variables have the value of 0? - objective-c

Question

I am trying to make it so that of the 4 variables, (squareType1, squareType2, squareType3, and squareType4) only one of them has a value of 0 but which variable it is should be random. The coding is off I know that but I just don't know how to fix it.
squareType1 = arc4random() %2;
squareType2 = arc4random() %2;
squareType3 = arc4random() %2;
squareType4 = arc4random() %2;
if (squareType2 == 0 || squareType3 == 0 || squareType4 == 0) {
squareType1 = 1;
}
if (squareType1 == 0 || squareType3 == 0 || squareType4 == 0) {
squareType2 = 1;
}
if (squareType2 == 0 || squareType1 == 0 || squareType4 == 0) {
squareType3 = 1;
}
if (squareType2 == 0 || squareType3 == 0 || squareType1 == 0) {
squareType4 = 1;
}

Answer 1

A simpler way to do this would be to set all 4 values to 1 initially and then randomly reset one of the variables to 0, e.g.
squareType1 = squareType2 = squareType3 = squareType4 = 1;
switch (arc4random() % 4)
{
case 0: squareType1 = 0; break;
case 1: squareType2 = 0; break;
case 2: squareType3 = 0; break;
case 3: squareType4 = 0; break;
}
Note that you will probably find life easier, in this instance and in general, if you refactor the four separate variables into a single array, e.g. int squareType[4];.