CSSMathValue

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

TheCSSMathValue interface of theCSS Typed Object Model API a base class for classes representing complex numeric values.

Interfaces based on CSSMathValue

Below is a list of interfaces based on the CSSMathValue interface.

Instance properties

CSSMathValue.operator: Indicates the operator that the current subtype represents.

Static methods

The interface may also inherit methods from its parent interface,CSSNumericValue.

Instance methods

The interface may also inherit methods from its parent interface,CSSNumericValue.

Examples

We create an element with awidth determined using acalc() function, thenconsole.log() theoperator.

html

<div>has width</div>

We assign awidth with a calculation

css

div {  width: calc(30% - 20px);}

We add the JavaScript

const styleMap = document.querySelector("div").computedStyleMap();console.log(styleMap.get("width")); // CSSMathSum {values: CSSNumericArray, operator: "sum"}console.log(styleMap.get("width").operator); // 'sum'console.log(styleMap.get("width").values[1].value); // -20

TheCSSMathValue.operator returns"sum" becausestyleMap.get("width").values[1].value ); is-20: adding a negative number.