Using LESS variables in HTML Data Attribute in "quotes" - css

Question

I am currently converting code from SASS to LESS.
I have a problem with the following line of code:
&[data-rating = "#{counter - 0.5}"] { // THIS DOES NOT WORK
How can I work with variables and subtract 0.5 from my counter var and have it in a pair of quotes so that it can sit inside the HTML data attribute.
I have included two code examples so you can take the code and run it to see my results.
SASS:
.reviews-stars {
display: inline-block;
#for $i from 1 through 5 {
&[data-rating = "#{$i}"] {
.star:nth-child(-n + #{$i}):before {
color: green;
}
}
&[data-rating = "#{$i - 0.5}"] {
.star:nth-child(-n + #{$i}):before {
color: red;
}
}
}
}
LESS:
.looper-review-stars(#counter) when (#counter > 0) {
.looper-review-stars((#counter - 1)); // next iteration
&[data-rating = "#{counter}"] { // THIS WORKS
.star:nth-child(-n + #{counter}):before { // THIS WORKS
color: green;
}
}
// THIS DOES NOT WORK IT RETURNS THE STRING "#{counter - 0.5}"
&[data-rating = "#{counter - 0.5}"] { // THIS DOES NOT WORK
.star:nth-child(-n + #{counter}):before { // THIS WORKS
color: red;
}
}
}
.reviews-stars {
display: inline-block;
.looper-review-stars(5); // launch the loop
}

Answer 1

You can do it using a temporary variable like in the below snippet. Since selectors are strings I think it is better to keep all math operations away from it and in a separate statement.
.looper-review-stars(#counter) when (#counter > 0) {
.looper-review-stars((#counter - 1)); // next iteration
&[data-rating = "#{counter}"] {
.star:nth-child(-n + #{counter}):before {
color: green;
}
}
#temp: #counter - .5; /* temporary variable */
&[data-rating = "#{temp}"] {
.star:nth-child(-n + #{counter}):before {
color: red;
}
}
}
.reviews-stars {
display: inline-block;
.looper-review-stars(5); // launch the loop
}