How to get CSS class property in Javascript?

Question

.test {
    width:80px;
    height:50px;
    background-color:#808080;
    margin:20px;
}

HTML -

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Answer 1

For modern browsers you can use getComputedStyle:

var elem,
    style;
elem = document.querySelector('.test');
style = getComputedStyle(elem);
style.marginTop; //`20px`
style.marginRight; //`20px`
style.marginBottom; //`20px`
style.marginLeft; //`20px`

margin is a composite style, and not reliable cross-browser. Each of -top -right, -bottom, and -left should be accessed individually.

fiddle