Is it possible to nest variables within variables in SASS?

Question

I have a mixin that accepts an argument that I want to pass into a variable.

@mixin my_mixin($arg) {
  background-color: $state-#{$arg}-text;
}

Answer 1

Interpolation of variable names is currently not possible in SASS. Here is the issue that discusses.

However, you may use interpolation of placeholders:

%my-dark-styles {
    background-color: #000;
}
%my-white-styles {
    background-color: #FFF;
}

@mixin my_mixin($arg) {
    @extend %my-#{$arg}-styles;
}

.header {
    @include my_mixin("dark");
}
.footer {
    @include my_mixin("white");
}

This compiles to:

.header {
  background-color: #000;
}

.footer {
  background-color: #FFF;
}