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

Browser compatibility

See also

• Temporal.Instant
• Temporal.Instant.prototype.toString()
• Temporal.Instant.prototype.toJSON()
• Temporal.Instant.prototype.toLocaleString()