CSSMathValue

Limited availability

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

The CSSMathValue interface of the CSS Typed Object Model API a base class for classes representing complex numeric values.

CSSStyleValue CSSNumericValue CSSMathValue

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 a width determined using a calc() function, then console.log() the operator.

html

<div>has width</div>

We assign a width with a calculation

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

We add the JavaScript

js
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

The CSSMathValue.operator returns "sum" because styleMap.get("width").values[1].value ); is -20: adding a negative number.