HTML | DOM Style flexBasis Property

Last Updated : 09 Aug, 2022

The DOM Style flexBasis property is used to set or return the initial length of a flexible item.

Note: If the element is not a flexible item, this property would have no effect.

Syntax:

It returns the flexBasis Property:

object.style.flexBasis

It used to set the flexBasis Property:

object.style.flexBasis = "number | auto | initial | inherit"

Return Values: It returns a string value, which represents the flex-basis property of an element.

Property Values:

number: This is used to specify the initial length in terms of fixed the length units or a percentage.
auto: This is used to set the length according to the length of the flexible item. The length will however, be according to the content if length is not specified. This is the default value.
initial: This is used to set this property to its default value.
inherit: This inherits the property from its parent.

Example-1: Using the number value.

html

<!DOCTYPE html>
<html>
 
<head>
    <title>
        DOM Style flexBasis property
    </title>
 
    <style>
        .main {
            width: 300px;
            height: 150px;
            border: 1px solid;
            display: flex;
        }
         
        .main div {
            width: 250px;
            height: 150px;
            font-size: 2rem;
            text-align: center;
        }
    </style>
</head>
 
<body>
    <h1 style="color: green">
      GeeksforGeeks
  </h1>
    <b>DOM Style flexBasis</b>
 
    <p>
      Click the button to change the value
      of the flexBasis to "100px"
    </p>
 
    <div class="main">
        <div style="background-color:green;">
            Geeks</div>
        <div id="div1"
             style="background-color:lightgreen;">
            For</div>
        <div style="background-color:green;">
            Geeks</div>
    </div>
 
    <button onclick="changeFlexBasis()">
        Change flexBasis
    </button>
 
    <script>
        function changeFlexBasis() {
            document.querySelector(
                '#div1').style.flexBasis = "100px";
        }
    </script>
 
</body>
 
</html>

Output:

Before clicking the button:

length-before

After clicking the button:

length-after

Example-2: Using the auto value.

html

<!DOCTYPE html>
<html>
<head>
    <title>
        DOM Style flexBasis property
    </title>
 
    <style>
        .main {
            width: 300px;
            height: 150px;
            border: 1px solid;
            display: flex;
        }
         
        .main div {
            width: 250px;
            height: 150px;
            font-size: 2rem;
            text-align: center;
        }
         
        #div1 {
            flex-basis: 50px;
        }
    </style>
</head>
 
<body>
    <h1 style="color: green">
      GeeksforGeeks
  </h1>
    <b>DOM Style flexBasis</b>
 
    <p>
      Click the button to change the
      value of the flexBasis to "auto"
    </p>
 
    <div class="main">
        <div style="background-color:green;">
            Geeks</div>
        <div id="div1" 
             style="background-color:lightgreen;">
            For</div>
        <div style="background-color:green;">
            Geeks</div>
    </div>
 
    <button onclick="changeFlexBasis()">
        Change flexBasis
    </button>
 
    <script>
        function changeFlexBasis() {
            document.querySelector(
                '#div1').style.flexBasis = "auto";
        }
    </script>
 
</body>
 
</html>

Output:

Before clicking the button:

auto-before

After clicking the button:

auto-after

Example-3: Using the initial value.

html

<!DOCTYPE html>
<html>
 
<head>
    <title>
        DOM Style flexBasis property
    </title>
 
    <style>
        .main {
            width: 300px;
            height: 150px;
            border: 1px solid;
            display: flex;
        }
         
        .main div {
            width: 250px;
            height: 150px;
            font-size: 2rem;
            text-align: center;
        }
         
        #div1 {
            flex-basis: 50px;
        }
    </style>
</head>
 
<body>
    <h1 style="color: green">
      GeeksforGeeks
  </h1>
    <b>DOM Style flexBasis</b>
 
    <p>
      Click the button to change the 
      value of the flexBasis to "initial"
    </p>
 
    <div class="main">
        <div style="background-color:green;">
            Geeks</div>
        <div id="div1" style="background-color:lightgreen;">
            For</div>
        <div style="background-color:green;">
            Geeks</div>
    </div>
 
    <button onclick="changeFlexBasis()">
        Change flexBasis
    </button>
 
    <script>
        function changeFlexBasis() {
            document.querySelector(
                '#div1').style.flexBasis = "initial";
        }
    </script>
 
</body>
 
</html>

Output:

Before clicking the button:

initial-before

After clicking the button:

initial-after

Example-4: Using the inherit value.

html

<!DOCTYPE html>
<html>
 
<head>
    <title>
        DOM Style flexBasis property
    </title>
 
    <style>
        #parent {
            flex-basis: 50%;
        }
         
        .main {
            width: 300px;
            height: 150px;
            border: 1px solid;
            display: flex;
        }
         
        .main div {
            width: 250px;
            height: 150px;
            font-size: 2rem;
            text-align: center;
        }
         
        #div1 {
            flex-basis: 50px;
        }
    </style>
</head>
 
<body>
    <h1 style="color: green">
      GeeksforGeeks
  </h1>
    <b>DOM Style flexBasis</b>
 
    <p>
      Click the button to change the value
      of the flexBasis to "inherit"
    </p>
    <div id="parent">
        <div class="main">
            <div style="background-color:green;">
                Geeks</div>
            <div id="div1" 
                 style="background-color:lightgreen;">
                For</div>
            <div style="background-color:green;">
                Geeks
            </div>
        </div>
    </div>
    <button onclick="changeFlexBasis()">
        Change flexBasis
    </button>
 
    <script>
        function changeFlexBasis() {
            document.querySelector(
                '#div1').style.flexBasis = "inherit";
        }
    </script>
 
</body>
 
</html>