Temporal.Duration.prototype.valueOf()
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The valueOf() method of Temporal.Duration instances throws a TypeError, which prevents Temporal.Duration instances from being implicitly converted to primitives when used in arithmetic or comparison operations.
Syntax
valueOf()
Parameters
None.
Return value
None.
Exceptions
TypeError-
Always thrown.
Description
Because both primitive conversion and number conversion call valueOf() before toString(), if valueOf() is absent, then an expression like duration1 > duration2 would implicitly compare them as strings, which may have unexpected results such as "PT3S" > "PT1M". By throwing a TypeError, Temporal.Duration instances prevent such implicit conversions. You need to explicitly convert them to numbers using Temporal.Duration.prototype.total(), or use the Temporal.Duration.compare() static method to compare them.
Examples
Arithmetic and comparison operations on Temporal.Duration
All arithmetic and comparison operations on Temporal.Duration instances should use the dedicated methods or convert them to primitives explicitly.
const duration1 = Temporal.Duration.from({ seconds: 3 });
const duration2 = Temporal.Duration.from({ minutes: 1 });
duration1 > duration2; // TypeError: can't convert Duration to primitive type
duration1.total("seconds") > duration2.total("seconds"); // false
Temporal.Duration.compare(duration1, duration2); // -1
duration1 + duration2; // TypeError: can't convert Duration to primitive type
duration1.total("seconds") + duration2.total("seconds"); // 63
duration1.add(duration2).toString(); // "PT1M3S"
Specifications
| Specification |
|---|
| Temporal proposal # sec-temporal.duration.prototype.valueof |
Browser compatibility
BCD tables only load in the browser