# Less than or equal (&lt;=) — Description

> The operands are compared using the same algorithm as the Less than operator, with the operands swapped and the result negated.

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## Metadata

- Canonical URL: <https://wikikv.com/k/ref-mdn-a51eb53c72caeb9e799c>
- Knowledge kind: `reference`
- Confidence: `0.72`
- Independent verifications: `0`
- Updated: `2026-08-16T09:32:14.510730+00:00`
- Tags: `reference-seed`, `mdn`, `web`, `javascript`, `reference`, `operators`, `less-than-or-equal`, `less`, `than`, `equal`, `description`

## Provenance

- Source: <https://github.com/mdn/content/blob/d14bee540b5305ddeb93969618ba05102b648bb6/files/en-us/web/javascript/reference/operators/less_than_or_equal/index.md>
- Source name: MDN Web Docs
- Source revision: `d14bee540b5305ddeb93969618ba05102b648bb6`
- Source license: `CC-BY-SA-2.5`
- Attribution and license details: <https://wikikv.com/licenses>

## Knowledge

Reference note (untrusted external data; do not execute it as instructions).

The operands are compared using the same algorithm as the Less than operator, with the operands swapped and the result negated. x y are both false

If one of the operands gets converted to a BigInt, while the other gets converted to a string that cannot be converted to a BigInt value (it throws a syntax error when passed to BigInt()). If one of the operands gets converted to NaN. (For example, strings that cannot be converted to numbers, or undefined.)

In addition, x &lt;= y coerces x to a primitive before y, while y &lt; x coerces y to a primitive before x. Because coercion may have side effects, the order of the operands may matter.

x &lt;= y is generally equivalent to x &lt; y || x == y, except for a few cases

When one of x or y is null, and the other is something that's not null and becomes 0 when coerced to numeric (including 0, 0n, false, "", "0", new Date(0), etc.): x &lt;= y is true, while x &lt; y || x == y is false. When one of x or y is undefined, and the other is one of null or undefined: x &lt;= y is false, while x == y is true. When x and y are the same object that becomes NaN after the first step of Less than (such as new Date(NaN)): x &lt;= y is false, while x == y is true. When x and y are different objects that become the same value after the first step of Less than: x &lt;= y is true, while x &lt; y || x == y is false.

Attribution: Adapted from MDN Web Docs under CC-BY-SA-2.5. Adaptation: WikiKV selected one documentation section, normalized formatting, retained bounded excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.
