Temporal.PlainYearMonth.prototype.toString()

The toString() method of {{jsxref("Temporal.PlainYearMonth")}} instances returns a string representing this year-month in the RFC 9557 format.

Syntax#

toString()
toString(options)

Parameters#

• options {{optional_inline}}
• : An object containing the following property:
  • calendarName {{optional_inline}}
  • : Whether to show the calendar annotation ([u-ca=calendar_id]) in the return value. Possible values are:
    • "auto" (default)
    • : Include the calendar annotation if the calendar is not "iso8601". The reference day is included if the calendar is not "iso8601".
    • "always"
    • : Always include the calendar annotation. The reference day is always included too.
    • "never"
    • : Never include the calendar annotation. This makes the returned string not recoverable to the same {{jsxref("Temporal.PlainYearMonth")}} instance, although the year-month value still remains the same. The reference day is included if the calendar is not "iso8601".
    • "critical"
    • : Always include the calendar annotation, and add a critical flag: [!u-ca=calendar_id]. Useful when sending the string to certain systems, but not useful for Temporal itself. The reference day is always included too.

Return value#

A string in the RFC 9557 format representing this year-month. The calendar annotation is included as specified. The reference day is included if a calendar annotation is included or if the calendar is not "iso8601".

Exceptions#

• {{jsxref("RangeError")}}
• : Thrown if any of the options is invalid.
• {{jsxref("TypeError")}}
• : Thrown if options is not an object or undefined.

Examples#

Using toString()#

const ym = Temporal.PlainYearMonth.from({ year: 2021, month: 8 });
console.log(ym.toString()); // '2021-08'

const ym2 = Temporal.PlainYearMonth.from({
  year: 5781,
  monthCode: "M08",
  calendar: "hebrew",
});
console.log(ym2.toString()); // '2021-04-13[u-ca=hebrew]'

Using options#

const isoYM = Temporal.PlainYearMonth.from({ year: 2021, month: 8 });
const ym = Temporal.PlainYearMonth.from({
  year: 5781,
  monthCode: "M08",
  calendar: "hebrew",
});
console.log(isoYM.toString({ calendarName: "auto" })); // '2021-08'
console.log(ym.toString({ calendarName: "auto" })); // '2021-04-13[u-ca=hebrew]'
console.log(isoYM.toString({ calendarName: "always" })); // '2021-08-01[u-ca=iso8601]'
console.log(ym.toString({ calendarName: "always" })); // '2021-04-13[u-ca=hebrew]'
console.log(isoYM.toString({ calendarName: "never" })); // '2021-08'
console.log(ym.toString({ calendarName: "never" })); // '2021-04-13'
console.log(isoYM.toString({ calendarName: "critical" })); // '2021-08-01[!u-ca=iso8601]'
console.log(ym.toString({ calendarName: "critical" })); // '2021-04-13[!u-ca=hebrew]'

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("Temporal.PlainYearMonth")}}
• {{jsxref("Temporal/PlainYearMonth/from", "Temporal.PlainYearMonth.from()")}}
• {{jsxref("Temporal/PlainYearMonth/toJSON", "Temporal.PlainYearMonth.prototype.toJSON()")}}
• {{jsxref("Temporal/PlainYearMonth/toLocaleString", "Temporal.PlainYearMonth.prototype.toLocaleString()")}}