z-index

The z-index CSS property specifies the stack level of the box in the current stacking context and whether the box establishes a local stacking context.

Syntax

CSS

z-index: value;

JS

object.style.zIndex = "value";

Initial

auto

<!doctype html>
<html>
<head>
    <style>
        img
        {
            position: absolute;
        }
        img:nth-of-type(1)
        {
            background-color: red;
        }
        img:nth-of-type(2)
        {
            background-color: green;
            left: 50px;
        }
        img:nth-of-type(3)
        {
            background-color: blue;
            left: 100px;
        }
    </style>
</head>
<body>
    <button onmouseover="myfunction(innerHTML)">initial</button>
    <button onmouseover="myfunction(innerHTML)">auto</button>
    <button onmouseover="myfunction(innerHTML)">integer</button><br>
    <img alt="Happy Face" src="/assets/svg/HappyFace.svg">
    <img alt="Happy Face" src="/assets/svg/HappyFace.svg">
    <img alt="Happy Face" src="/assets/svg/HappyFace.svg">
    <script>
        function myfunction(myparameter)
        {
            const myelements = document.querySelectorAll("img");
            for(let i = 0; i < myelements.length; ++i)
            {
                myelements[i].style.zIndex = myparameter;
                if(myparameter == "integer")
                {
                    myelements[i].style.zIndex = myelements.length - i;
                }
            }
        }
    </script>
</body>
</html>

4 · JS · Internal

<!doctype html>
<html>
<head>
    <style>
        img
        {
            position: absolute;
        }
        img:nth-of-type(1)
        {
            background-color: red;
        }
        img:nth-of-type(2)
        {
            background-color: green;
            left: 50px;
        }
        img:nth-of-type(3)
        {
            background-color: blue;
            left: 100px;
        }
    </style>
</head>
<body>
    <button>initial</button>
    <button>auto</button>
    <button>integer</button><br>
    <img alt="Happy Face" src="/assets/svg/HappyFace.svg">
    <img alt="Happy Face" src="/assets/svg/HappyFace.svg">
    <img alt="Happy Face" src="/assets/svg/HappyFace.svg">
    <script>
        function myfunction(myparameter)
        {
            const myelements = document.querySelectorAll("img");
            for(let i = 0; i < myelements.length; ++i)
            {
                myelements[i].style.zIndex = myparameter;
                if(myparameter == "integer")
                {
                    myelements[i].style.zIndex = myelements.length - i;
                }
            }
        }
        const myelements = document.querySelectorAll("button");
        for(let myelement of myelements)
        {
            myelement.addEventListener("mouseover", function(){myfunction(myelement.innerHTML)});
        }
    </script>
</body>
</html>

Syntax

CSS

JS

Values

Initial

Examples

1 · auto

2 · integer

3 · JS · Inline

4 · JS · Internal

Links

Properties

External