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CSS

Posted by Lucas Santos
Lucas Santos
19,315 Points

SASS interpolation question

So in this example:

@for $i from 1 through 3{
.item_#{$i}{
width: $i * 100px;
}
}

Why is it that in the width: $i * 100px; it is just $i and not #{$i}

also the other way around why can't we just use .item_$i instead of .item_#{$i}

1 Answer

Máté Végh
Máté Végh
25,607 Points

Sass variables can only store values. For dynamic selectors like in this case, you need to use interpolation syntax, otherwise it will output an error.

For instance:

$selector: item;
$value: red;

// Right:
.#{$selector} {
  background: $value;
}

// Wrong:
.$selector {
  background: $value;
}
Lucas Santos
Lucas Santos
19,315 Points

So interpolation is specifically for selectors rite.. other than that you can use an argument with out interpolation to calculate values like the width correct?

Máté Végh
Máté Végh
25,607 Points

You could also store a property into a variable, than use it with interpolation. For instance:

$bg: background;

.item {
  #{$bg}: red;
}

But yes, you are right, interpolation is used for selectors most of the time, and regular variables are used for values.

Lucas Santos
Lucas Santos
19,315 Points

I see thanks Matt appreciate it!