Temporal.PlainTime.prototype.valueOf()

The valueOf() method of {{jsxref("Temporal.PlainTime")}} instances throws a {{jsxref("TypeError")}}, which prevents Temporal.PlainTime instances from being implicitly converted to primitives when used in arithmetic or comparison operations.

Syntax#

valueOf()

Parameters#

None.

Return value#

None.

Exceptions#

• {{jsxref("TypeError")}}
• : Always thrown.

Description#

Because both primitive conversion and number conversion call valueOf() before toString(), if valueOf() is absent, then an expression like time1 > time2 would implicitly compare them as strings, which may have unexpected results. By throwing a TypeError, Temporal.PlainTime instances prevent such implicit conversions. You need to explicitly convert them to strings using {{jsxref("Temporal/PlainTime/toString", "Temporal.PlainTime.prototype.toString()")}}, or use the {{jsxref("Temporal/PlainTime/compare", "Temporal.PlainTime.compare()")}} static method to compare them.

Examples#

Arithmetic and comparison operations on Temporal.PlainTime#

All arithmetic and comparison operations on Temporal.PlainTime instances should use the dedicated methods or convert them to primitives explicitly.

const time1 = Temporal.PlainTime.from("00:00:00");
const time2 = Temporal.PlainTime.from("12:00:00");
time1 > time2; // TypeError: can't convert PlainTime to primitive type
Temporal.PlainTime.compare(time1, time2); // -1

time2 - time1; // TypeError: can't convert PlainTime to primitive type
time2.since(time1).toString(); // "PT12H"

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("Temporal.PlainTime")}}
• {{jsxref("Temporal/PlainTime/toString", "Temporal.PlainTime.prototype.toString()")}}
• {{jsxref("Temporal/PlainTime/toJSON", "Temporal.PlainTime.prototype.toJSON()")}}
• {{jsxref("Temporal/PlainTime/toLocaleString", "Temporal.PlainTime.prototype.toLocaleString()")}}