Check if an array contains a value matching some criterias

True when at least one item satisfies the predicate.

JavaScriptNode.js & browsers Version 1.0.0 · MIT · .md

function contains(values, predicate) { return values.some(predicate); }

Usage

contains([10, 20, 30], n => n > 25); // → true
contains([10, 20, 30], n => n > 100); // → false
contains([], () => true); // → false

Lines marked → were executed in Node.js 22 and in headless Chromium, and each result was compared with the value shown. Lines marked e.g. are illustrative.

Know the limits

• some stops at the first match and returns false for an empty array, as the last line shows.
• The predicate also receives the index and the array; wrap functions with optional parameters, as in Create a function that accepts a single argument.

The function above is the code the usage lines run. It does not validate its arguments; add checks where it receives untrusted input.

Keep exploring

• Check whether all values are equal — Compare every item with the first using Object.is.
• Check whether an object is empty — Check for own enumerable string keys on a JSON object.
• Check whether an integer is even — Test parity for safe integers, including zero and negative values.