The Temporal.Instant.compare() static method returns a number (-1, 0, or 1) indicating whether the first instant comes before, is the same as, or comes after the second instant. It is equivalent to comparing the epochNanoseconds of the two instants.

Syntax

Temporal.Instant.compare(instant1, instant2)

Parameters

instant1

A string or a Temporal.Instant instance representing the first instant to compare. It is converted to a Temporal.Instant object using the same algorithm as Temporal.Instant.from().

instant2

The second instant to compare, converted to a Temporal.Instant object using the same algorithm as instant1.

Return value

Returns -1 if instant1 comes before instant2, 0 if they are the same, and 1 if instant1 comes after instant2.

Examples

Using Temporal.Instant.compare()

const instant1 = Temporal.Instant.from("2021-08-01T12:34:56Z");
const instant2 = Temporal.Instant.from("2021-08-01T12:34:56Z");

console.log(Temporal.Instant.compare(instant1, instant2)); // 0

const instant3 = Temporal.Instant.from("2021-08-01T13:34:56Z");
console.log(Temporal.Instant.compare(instant1, instant3)); // -1

Sorting an array of instants

The purpose of this compare() function is to act as a comparator to be passed to Array.prototype.sort() and related functions.

const instants = [
  Temporal.Instant.from("2021-08-01T12:34:56Z"),
  Temporal.Instant.from("2021-08-01T12:34:56+01:00"),
  Temporal.Instant.from("2021-08-01T12:34:56-01:00"),
];

instants.sort(Temporal.Instant.compare);
console.log(instants.map((instant) => instant.toString()));
// [ '2021-08-01T11:34:56Z', '2021-08-01T12:34:56Z', '2021-08-01T13:34:56Z' ]

Specifications

Browser compatibility

See also

• Temporal.Instant
• Temporal.Instant.prototype.equals()