Note: This feature is available in Web Workers.
The unit read-only property of the CSSUnitValue interface returns a string indicating the unit type.
A string indicating the unit type, such as "em", "px", "%", etc.
The following code creates a CSSPositionValue from individual CSSUnitValue constructors, then queries the CSSUnitValue.unit.
const pos = new CSSPositionValue(
new CSSUnitValue(5, "px"),
new CSSUnitValue(10, "em"),
);
console.log(pos.x.unit); // "px"
console.log(pos.y.unit); // "em"CSSUnitValue.value