files/en-us/web/api/cssfontfeaturevaluesmap/set/index.md
{{APIRef("CSSOM")}}{{SeeCompatTable}}
The set() method of {{domxref("CSSFontFeatureValuesMap")}} instances adds a new entry with a specified key and value to this CSSFontFeatureValuesMap, or updates an existing entry if the key already exists.
set(key, value)
key
CSSFontFeatureValuesMap object. Can be any value.value
CSSFontFeatureValuesMap object. Must be an integer that matches the index of the alternative font feature.The CSSFontFeatureValuesMap object.
The following example updates the value for swashy and adds a third declaration. This example is using @swash but also works with other feature value blocks.
@font-feature-values "MonteCarlo" {
@swash {
swishy: 1;
swashy: 2;
}
}
function logSwashes(value, key) {
console.log(`('${key}') = ${value}`);
}
// get the rules
const myRule = document.styleSheets[0].cssRules[0];
// log current swashes
myRule.swash.forEach(logSwashes); // logs "('swishy') = 1", "('swashy') = 2"
// update swash with the key swashy
myRule.swash.set("swashy", 3);
myRule.swash.forEach(logSwashes); // logs "('swishy') = 1", "('swashy') = 3"
// add new swash with the key swooshy
myRule.swash.set("swooshy", 2);
myRule.swash.forEach(logSwashes); // logs "('swishy') = 1", "('swooshy') = 2", "('swashy') = 3"
{{Specifications}}
{{Compat}}