Temporal.PlainMonthDay.prototype.equals()

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 equals() method of Temporal.PlainMonthDay instances returns true if this month-day is equivalent in value to another month-day (in a form convertible by Temporal.PlainMonthDay.from()), and false otherwise. They are compared both by their underlying ISO date values and their calendars.

Note: PlainMonthDay objects keep track of a reference ISO year, which is also used in the comparison. This year is automatically set when using the Temporal.PlainMonthDay.from() method, but can be set manually using the Temporal.PlainMonthDay() constructor, causing two equivalent month-days to be considered different if they have different reference years. For this reason, you should avoid using the constructor directly and prefer the from() method.

Syntax

equals(other)

Parameters

other: A string, an object, or a Temporal.PlainMonthDay instance representing the other month-day to compare. It is converted to a Temporal.PlainMonthDay object using the same algorithm as Temporal.PlainMonthDay.from().

const md1 = Temporal.PlainMonthDay.from("2021-08-01");
const md2 = Temporal.PlainMonthDay.from({ year: 2020, month: 8, day: 1 }); // Year doesn't matter
console.log(md1.equals(md2)); // true

const md3 = Temporal.PlainMonthDay.from("2021-08-01[u-ca=japanese]");
console.log(md1.equals(md3)); // false

const md4 = Temporal.PlainMonthDay.from("2021-08-02");
console.log(md1.equals(md4)); // false