Sass and combined child selector

问题:

I've just discovered Sass, and I've been so excited about it.

In my website I implement a tree-like navigation menu, styled using the child combinator (E > F).

Is there any way to rewrite this code with a simpler (or better) syntax in Sass?

#foo > ul > li > ul > li > a {
  color: red;
}

回答1:

Without the combined child selector you would probably do something similar to this:

foo {
  bar {
    baz {
      color: red;
    }
  }
}

If you want to reproduce the same syntax with >, you could to this:

foo {
  > bar {
    > baz {
      color: red;
    }
  }
}

This compiles to this:

foo > bar > baz {
  color: red;
}

---

Or in sass:

foo
  > bar
    > baz
      color: red

回答2:

For that single rule you have, there isn't any shorter way to do it. The child combinator is the same in CSS and in Sass/SCSS and there's no alternative to it.

However, if you had multiple rules like this:

#foo > ul > li > ul > li > a:nth-child(3n+1) {
    color: red;
}

#foo > ul > li > ul > li > a:nth-child(3n+2) {
    color: green;
}

#foo > ul > li > ul > li > a:nth-child(3n+3) {
    color: blue;
}

You could condense them to one of the following:

/* Sass */
#foo > ul > li > ul > li
    > a:nth-child(3n+1)
        color: red
    > a:nth-child(3n+2)
        color: green
    > a:nth-child(3n+3)
        color: blue

/* SCSS */
#foo > ul > li > ul > li {
    > a:nth-child(3n+1) { color: red; }
    > a:nth-child(3n+2) { color: green; }
    > a:nth-child(3n+3) { color: blue; }
}