Less.js Extend Selector Interpolation with Extend

Last Updated : 25 Oct, 2022

LESS is a simple CSS pre-processor that makes it possible to create manageable, customizable, and reusable style sheets for websites. LESS is a dynamic style sheet language that increases the working power of CSS. LESS is cross-browser compatible. CSS pre-processor is a scripting language that improves CSS and gets compiled into regular CSS syntax so that the web browser can use it. This also provides functionalities like variables, functions, mixins, and operations that enable us to build dynamic CSS.

Extend: LESS Extend is a pseudo-class that helps to merge different selectors, based on putting it with one that matches according to what it is referenced. We can use the LESS extend feature using the: extend keyword

Selector Interpolation with Extend:

Selector Interpolation with Extend. It is used to connect to the interpolated selector.
Extend is not able to match selectors with variables. If the selector contains a variable, extend will ignore it.

Syntax:

@{variable}:extend(.style) {}
@variable: .selector;

Example 1: The following examples demonstrates the use of Less.js Extend Selector Interpolation with Extend in Less file.

HTML

<!doctype html> 
<head> 
    <link rel="stylesheet" href="style.css" 
          type="text/css" /> 
</head> 
  
<body> 
    <div><br><br> 
        <h1><b>GeeksforGeeks</b></h1> 
        <h2 class="style"><b> 
          Learning Selector Interpolation with Extend</b></h2>         
    </div> 
</body> 
</html>

style. less: Create the less file.

CSS

@color: black; 
@bg: green; 
.style { 
    color: @color; 
    font-family: "Comic Sans MS"; 
    text-align: center; 
} 
h1 { 
    color: @bg; 
    text-align: center; 
} 
  
@{variable}:extend(.style) { 
} 
@variable: .selector; 

Now, to compile the above LESS code to CSS code, run the following command:

lessc style.less style.css

The compiled CSS file comes to be:

style.css

CSS

.style { 
    color: black; 
    font-family: "Comic Sans MS"; 
    text-align: center; 
} 
h1 { 
    color: green; 
    text-align: center; 
} 

Output:

Example 2: The following example demonstrates the use of Less.js Extend Selector Interpolation with Extend in Less file.

HTML

<!doctype html> 
    <head> 
      <link rel="stylesheet" href="style.css" 
            type="text/css" /> 
    </head> 
    <body> 
        <div><br><br> 
            <h1><b>GeeksforGeeks</b></h1> 
            <h2 class="Library"> 
               <b>Learning Selector Interpolation with Extend</b></h2> 
            <br><br><br>         
        </div> 
    </body> 
</html>

style. less:

CSS

@variable: .Library; 
@{variable} { 
    color: white; 
    text-align: center; 
} 
h1 { 
    color: green; 
    text-align: center; 
} 
div { 
    background-color: black; 
} 
.Library-class:extend(.Library) { 
} 

Now, to compile the above LESS code to CSS code, run the following command:

lessc style.less style.css

The compiled CSS file comes to be:

style.css

CSS

.Library, 
.Library-class { 
    color: white; 
    text-align: center; 
} 
h1 { 
    color: green; 
    text-align: center; 
} 
div { 
    background-color: black; 
} 