Temporal.Instant.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.Instant instances throws a TypeError, which prevents Temporal.Instant 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 instant1 > instant2 would implicitly compare them as strings, which may have unexpected results. By throwing a TypeError, Temporal.Instant instances prevent such implicit conversions. You need to explicitly convert them to numbers using Temporal.Instant.prototype.epochNanoseconds, or use the Temporal.Instant.compare() static method to compare them.
Examples
Arithmetic and comparison operations on Temporal.Instant
All arithmetic and comparison operations on Temporal.Instant instances should use the dedicated methods or convert them to primitives explicitly.
const instant1 = Temporal.Instant.fromEpochMilliseconds(0);
const instant2 = Temporal.Instant.fromEpochMilliseconds(1000);
instant1 > instant2; // TypeError: can't convert Instant to primitive type
instant1.epochNanoseconds > instant2.epochNanoseconds; // false
Temporal.Instant.compare(instant1, instant2); // -1
instant2 - instant1; // TypeError: can't convert Instant to primitive type
instant2.since(instant1).toString(); // "PT1S"
Specifications
| Specification |
|---|
| Temporal proposal # sec-temporal.instant.prototype.valueof |
Browser compatibility
BCD tables only load in the browser