Use the :only-child pseudo-class selector to select styles where the parent element has only one child element.

Use:only-child pseudo-class selector to select the style of the parent element with only one child element

CSS is an essential part of front-end development. It provides the basis for web pages. Provides rich styles to make our pages more beautiful and easy to read. Among them, pseudo-class selector is a very useful technology in CSS, which can select different elements and states for styling.

Among pseudo-class selectors, :only-child is a very useful selector, which can select the style of only one child element in the parent element. In actual development, we often need to set styles according to different situations. In this case, we can use :only-child to select a parent element with only one child element.

Below I will give a specific code example to demonstrate how to use the :only-child selector.

Suppose we have an HTML structure as follows:

<div class="parent">
  <p>这是唯一的子元素</p>
</div>

<div class="parent">
  <p>这是第一个子元素</p>
  <p>这是第二个子元素</p>
</div>

<div class="parent">
  <p>这是第一个子元素</p>
  <p>这是第二个子元素</p>
  <p>这是第三个子元素</p>
</div>

Now we want to style only the parent element in the first div that has only one child element. We can use the :only-child selector to accomplish this requirement. The specific code is as follows:

.parent:only-child {
  background-color: lightgreen;
  padding: 10px;
}

In the above code, we first use the .parent selector to select all elements with class parent, and then use :only-child to select parent elements with only one child element. Then set the background color of these elements to lightgreen and add 10 pixels of padding.

In this way, only the parent element of the first div with only one child element will apply the above style, and other divs will not be affected.

Through the above code examples, we can see that the actual application of the only-child selector is very simple. It can help us accurately select a parent element with only one child element, without having to manually judge each element.

To summarize, the :only-child selector is a very useful selector in CSS, which can help us select a parent element with only one child element. By rationally using this selector, we can set page styles more efficiently and improve development efficiency.

Hope the above content is helpful to you! Thanks for reading!

The above is the detailed content of Use the :only-child pseudo-class selector to select styles where the parent element has only one child element.. For more information, please follow other related articles on the PHP Chinese website!