Array.prototype.find(callback) returns the first element that passes your test. No match → undefined. It stops early and does not mutate the array (ES2015).
array.find((element, index, array) => test)
first truthy match → that element
no match → undefined
stops at the first hit (does not scan the rest)
filter() → all matches (array)
findIndex() → index of first match (−1 if none)Call array.find. Start with this line.
array.find(callback, thisArg?)| Call | What it does |
|---|---|
array.find(callback, thisArg?) | Primary signature. |
array.find(...) | Call with the arguments your case needs. |
Built into JavaScript. Call find(...) on an array instance — no import required.
array.find(callback, thisArg?)| Parameter | Description |
|---|---|
| callback | Required. Test function; truthy → return that element |
| index, array | Optional. Extra callback args when needed |
| Return Value | Description |
|---|---|
| * | First match, or undefined |
Return the first value greater than 20—later matches are ignored.
const numbers = [10, 25, 5, 40, 15];
const result = numbers.find((n) => n > 20);
console.log(result); // 250.10 > 20 is false.25 immediately.find already stopped.When nothing passes, you get undefined—check before using the result.
const numbers = [10, 25, 5, 40, 15];
const result = numbers.find((n) => n > 50);
if (result !== undefined) {
console.log(result);
} else {
console.log("No element found.");
}50.null, not [].!== undefined before use.Locate a user by username—common for lists of records.
const users = [
{ id: 1, username: "john_doe" },
{ id: 2, username: "jane_smith" },
{ id: 3, username: "bob_jones" }
];
const foundUser = users.find((user) => user.username === "jane_smith");
console.log(foundUser);id and username.user.username === "jane_smith".Array.prototype.find() is part of ES2015 (ES6). It has been available in evergreen browsers for years and in Node.js since version 4.
Supported in Chrome 45+, Firefox 25+, Safari 7.1+, Edge 12+, and Node 4+. Not available in Internet Explorer.
Bottom line: Safe for modern web and Node targets. Polyfill only if you must support Internet Explorer.
Get the position of the first match—or -1 when nothing passes.
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