CSS If Select Has Value

When writing CSS, it's often necessary to style elements based on their values. One way to do this is by using the :not() pseudo-class to exclude elements that don't have a certain value. However, this approach can get complicated if you're trying to target multiple values or if the values are nested within the element's structure.

Luckily, there's a simpler way to achieve this with CSS. You can use the attribute selector to target elements that have a certain value for a particular attribute. Here's how it works:

element[attribute="value"] {
  /* Styles here */
}

In this example, "element" is the HTML element you want to target (e.g. "p", "div", "input", etc.), "attribute" is the name of the attribute you want to select, and "value" is the value you want to match.

For instance, let's say you have a form with a text input field that users fill out with their email address. You want to apply a special style to this input field if it's not empty. Here's how you can do it:

<form>
  <label for="email">Email:</label>
  <input type="text" id="email" name="email">
</form>

input[name="email"][value=""] {
  /* Default styles here */
}

input[name="email"][value]:not([value=""]) {
  /* Special styles here */
}

In this example, we're using the attribute selector to target the "name" attribute of the input element with the value "email". We're also checking for two conditions: (1) the "value" attribute is empty (i.e. the input field is blank) and (2) the "value" attribute is not empty (i.e. the input field has a value).

In the first declaration block, we apply the default styles to the input field when it's empty (i.e. the value attribute is an empty string). In the second declaration block, we apply the special styles to the input field when it's not empty (i.e. the value attribute has a value other than an empty string).

Note that you can use other attributes besides "value" to target elements based on their values. For example, you can use the "href" attribute to select links with a certain URL:

a[href="https://example.com"] {
  /* Styles for links with the URL https://example.com */
}

Overall, using the attribute selector to target elements based on their values can make your CSS code more concise and easier to read.