Question

This one compiles:

.myclass {
    .mymixin(2);
}

.mymixin(@parameter) {
    width: ((@parameter*1)*12px);
}

This one does not:

.myclass {
    .mymixin(2);
}

.mymixin(@parameter) {
    width: ((@parameter-1)*12px);
}

Does anyone have a clue what’s the problem with the second one?

Answer 1

Less treats @parameter-1 as a variable as you can tell from the compiler error:

Error line 2: variable @parameter-1 is undefined

If you insert spaces it works as expected:

.mymixin(@parameter) {
    width: ((@parameter - 1)*12px);
}