after effects slider control code help

Question

I'm trying to make a slider that basically can act as a crossfader between a bunch of different layers (so as the slider goes up, it fades through several layers). This is what I've written, and I'm getting the error "Error: SyntaxError: Unexpected Token )" on the first line and I'm having trouble telling where the problem is. My code:

if(thisComp.layer("Null 1").effect("Slider Control")("Slider") <= 5)
{
    if(thisComp.layer("Null 1").effect("Slider Control")("Slider") <= 2.5)
    {
        out = linear("Null 1").effect("Slider Control")("Slider"), 0, 100, 0, 2.5);
    }
    else
    {
        out = linear("Null 1").effect("Slider Control")("Slider"), 0, 100, 2.5, 5);
        out = 100 - out;
    }
    }
}
else{
    out = 0;
}
out;

Thank you!!

Answer 1

The error message is telling you that you've got a stray bracket, so count your brackets and see if the (s match the )s. Spoiler alert: they don't.

I can see two cases: after each linear function call you have a closing bracket after the "Null 1" string that isn't matched by an opening bracket. And "Null 1" on its own is just treated as a string, not a layer, so that's another problem.

I'm assuming you mean thisComp.layer("Null 1") which is a reference to a layer. So

out = linear("Null 1").effect("Slider Control")("Slider"), 0, 100, 0, 2.5);

should be

out = linear(thisComp.layer("Null 1").effect("Slider Control")("Slider"), 0, 100, 0, 2.5);