Scss how convert string to numeric value

Question

I want to perform mathematical operations using the font-size information with the function below. I remove the rem unit information of $font-size using the sass build-in string functions, but then I cannot perform mathematical operations because the value type is string.

Is there a way to convert a string value type to numeric value type in sass?

@use "../abstracts/variables" as *;
@use "sass:math";

@function em($value, $font-size) {
   
  $length: str-length(#{$font-size}); //sample-think about it font-size 1.125rem

  $trim: ($length - 3);

  $data: str-slice(#{$font-size}, 1, $trim);

  $result: math.div($value, $data);

  @return $result + "em";
}

Answer 1

It would probably be better to use a helper function to remove the unit of $font-size such as this one.

@function stripUnit($number) {
    @if meta.type-of($number) == "number" and not math.is-unitless($number) {
      @return math.div($number, $number * 0 + 1);
    }
 
    @return $number;
}

@function em($value, $font-size) {
  $data: strip-unit($font-size);
  $result: math.div($value, $data);

  @return $result + "em";
}