目录

Window getComputedStyle()

Example

Get the computed background color of an element:

const element = document.getElementById("test");
const cssObj = window.getComputedStyle(element, null);

let bgColor = cssObj.getPropertyValue("background-color");
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More examples below.


Description

The getComputedStyle() method gets the computed CSS properties and values of an HTML element.

The getComputedStyle() method returns a CSSStyleDeclaration object.


Computed Style

The computed style is the style used on the element after all styling sources have been applied.

Style sources: external and internal style sheets, inherited styles, and browser default styles.


Syntax

window.getComputedStyle( element, pseudoElement)

Parameters

Parameter Description
element Required.
The element to get the computed style for.
pseudoElement Optional.
A pseudo-element to get.

Return Value

Type Description
An object A CSSStyleDeclaration object with all the CSS properties and values of the element.


More Examples

Get all the computed styles from an element:

const element = document.getElementById("test");
const cssObj = window.getComputedStyle(element, null);

let text = "";
for (x in cssObj) {
  cssObjProp = cssObj.item(x)
  text += cssObjProp + " = " + cssObj.getPropertyValue(cssObjProp) + "<br>";
}
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Get computed font size of the first letter in an element (using pseudo-element):

const element = document.getElementById("test"); const cssObj = window.getComputedStyle(element, ":first-letter")

let size = cssObj.getPropertyValue("font-size");
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Browser Support

getComputedStyle() is supported in all browsers:

Chrome Edge Firefox Safari Opera IE
Yes Yes Yes Yes Yes 9-11