What is the difference between '>' and a space in CSS selectors?_问答_开发者

What is the difference between '>' and a space in CSS selectors?

开发者 https://www.devze.com 2022-12-27 08:34 出处：网络

What\'s the point using this syntax di开发者_如何学JAVAv.card > div.name What\'s the difference between this

What's the point using this syntax

di开发者_如何学JAVAv.card > div.name

What's the difference between this

div.card div.name

A > B will only select B that are direct children to A (that is, there are no other elements inbetween).

A B will select any B that are inside A, even if there are other elements between them.

> is the child selector. It specifies only immediate child elements and not any descendant (including grandchildren, grand-grandchildren etc.) as in the second example without the >.

The child selector is not supported by IE 6 and lower. A great compatibility table is here.

> vs. Space

Consider the two scenarios div > span { } vs. div span { }

Here, the (space) selects all the all the <span> elements inside <div> element even if they are nested inside more than one element. The > selects all the children of <div> element but if they are not inside another element.

Take a look at two examples:

> (Greater than):

div > span {
  color: #FFBA00 ;
}

<body>
  <div>
    <div>
      <span>Hello...</span>
      <p><span>Hello!</span></p>
    </div>

    <span>World!</span>
  </div>
</body>

This one just selects the <span>Hello...</span> (because it's immediately after the nested div tag), and <span>World!</span> and it won't look for the <span> inside <p> tag because it's not immediately after a div tag.

Space

div span {
  color: #0A0 ;
}

<body>
  <div>
    <div>
      <span>Hello...</span>
      <p><span>Hello!</span></p>
    </div>

    <span>World!</span>
  </div>
</body>

This one selects all the span tags, even if they are nested inside other tags.

div.card > div.name matches <div class='card'>....<div class='name'>xxx</div>...</div> but it doesn't match <div class='card'>....<div class='foo'> ... <div class='name'>xxx</div>..</div>....</div>

div.card div.name matches both.

That is, the > selector makes sure that the selected element on the right side of the > is an immidiate child of the element on its left side.

The syntax without the > matches any <div class='name'> that is a descendant (not only a child) of <div class='card'>.

A > B selects B if it's a direct children of A, whereas A B selects B whether it is a direct children of B or not.

<p> USING SPACE </p>

<style>
  .a .b {
    background-color: red;
  }
</style>

<span class="a">
  a
  <br>
  <span class="b"> a b</span>
  <br>

  <span class="c">
    <span class="b"> a b c</span>
  </span>
</span>

<br><br>
<p> USING GREATER THAN SIGN</p>

<style>
  .x > .y {
    background-color: red;
  }
</style>

<span class="x">
  x
  <br>
  <span class="y"> x y</span>
  <br>

  <span class="z">
    <span class="y"> x y z</span>
  </span>
</span>