Z-INDEX

The z-index 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";

VALUES


            <'z-index'> = auto | <integer> | inherit


            auto

Automatically specified by the user agent.


            <integer>

Specifies one or more decimal digits (0-9).


            inherit

Specifies the same value as the parent.

INITIAL

auto

EXAMPLES

AUTO

INTEGER

JS

<!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: 40px;
        }
        img:nth-of-type(3) {
            background-color: blue;
            left: 80px;
        }
    </style>
    <script>
        function mouseover(value) {
            var elements = document.getElementsByTagName("img");
            for (var i = 0; elements.length; ++i) {
                elements[i].style.zIndex = value;
                if (value == "integer") {
                    elements[i].style.zIndex = elements.length - i;
                }
            }
        }
    </script>
</head>
<body>
    <input onmouseover="mouseover(value)" type="button" value="auto">
    <input onmouseover="mouseover(value)" type="button" value="integer"><br>
    <img alt="Happy Face" src="/assets/png/HappyFace.png">
    <img alt="Happy Face" src="/assets/png/HappyFace.png">
    <img alt="Happy Face" src="/assets/png/HappyFace.png">
</body>
</html>

LINKS

World Wide Web Consortium (W3C)