web api instance method
CSSFontFeatureValuesMap: has() method
Limited availability
The has() method of the CSSFontFeatureValuesMap interface returns a boolean indicating whether an entry with the specified key exists in this CSSFontFeatureValuesMap or not.
Syntax
has(property)
Parameters
key- : The key of the value to return from the
CSSFontFeatureValuesMapobject.
- : The key of the value to return from the
Return value
The value associated with the specified key in the CSSFontFeatureValuesMap object. If the key can’t be found, undefined is returned.
Examples
Basic usage
The following example returns true or false if the @swash rule contains the key. This example is using @swash but also works with other feature value blocks.
CSS
@font-feature-values "MonteCarlo" {
@swash {
swishy: 1;
swashy: 2;
}
}
JavaScript
// get the rules
const myRule = document.styleSheets[0].cssRules[0];
console.log(myRule.swash.has("swishy")); // logs true
console.log(myRule.swash.has("swooshy")); // logs false
Specifications
SpecificationsStandards references are available on the canonical MDN page.
Browser compatibility
Browser compatibilityCompatibility data is available on the canonical MDN page.