flex-basis

Description
Syntax
Examples
Links

Description

The flex-basis property for CSS sets the flex-basis longhand, which specifies the flex basis: the initial main size of the flex item, before free space is distributed according to the flex factors.

Syntax

CSS

flex-basis: value;

JS

object.style.flexBasis = "value";

Values

<'flex-basis'> = content | <'width'>

content

Indicates an automatic size based on the flex item's content.

<'width'> = auto | <length-percentage> | min-content | max-content | fit-content( <length-percentage> )

auto

Automatically specified by the user agent.

<length-percentage> =
    <length> |
    <percentage>

<length>

Specifies the length using a number followed by a unit of measurement.

<percentage>

Specifies the percentage using a number followed by a percent sign (%).

min-content

Represents the largest min-content contribution of the items occupying the track.

max-content

Represents the largest max-content contribution of the items occupying the track.

fit-content()

Represents the formula max(minimum, min(limit, max-content)), where minimum represents an auto minimum (which is often, but not always, equal to a min-content minimum), and limit is the track sizing function passed as an argument to fit-content(). This is essentially calculated as the smaller of minmax(auto, max-content) and minmax(auto, limit).

Initial

auto

Examples

1 · auto

2 · content

3 · length

4 · max-content

5 · min-content

6 · percentage

7 · JS

<!doctype html>
<html>
<head>
    <style>
        .myclass
        {
            display: flex;
        }
        .myclass > div
        {
            background-image: linear-gradient(135deg, white, lightgray);
        }
    </style>
</head>
<body>
    <button>initial</button>
    <button>auto</button>
    <button>content</button>
    <button value="100px">length</button>
    <button>max-content</button>
    <button>min-content</button>
    <button value="20%">percentage</button>
    <div class="myclass">
        <div>flex-basis</div>
        <div>flex-basis</div>
        <div>flex-basis</div>
        <div>flex-basis</div>
        <div>flex-basis</div>
    </div>
    <script>
        function myfunction(myparameter)
        {
            const mytarget = myparameter.target;
            const myproperty = mytarget.value || mytarget.innerHTML;
            for(const mydiv of document.querySelectorAll(".myclass > div"))
            {
                mydiv.style.flexBasis = myproperty;
            }
        }
        for(const mybutton of document.querySelectorAll("button"))
        {
            mybutton.addEventListener("mouseover", myfunction);
        }
    </script>
</body>
</html>