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function func1() {}
function func2(a, b) {}
console.log(func1.length);
// Expected output: 0
console.log(func2.length);
// Expected output: 2
Property attributes of Function.prototype.length | |
|---|---|
length , , .
.
, arguments.length
(local) .
Function length .
.
.
arguments.length
.
Function function . length
1.
Function.prototype . Function.prototype
length 0.
console.log(Function.length); // 1
console.log((() => {}).length); // 0
console.log(((a) => {}).length); // 1
console.log(((a, b) => {}).length); // 2 etc.
console.log(((...args) => {}).length);
// 0,
console.log(((a, b = 1, c) => {}).length);
// 1,
| Specification |
|---|
| ECMAScript 2027 LanguageSpecification # sec-function-instances-length |
This page was last modified on 2025 2 11 by MDN contributors.
FunctionObject/FunctionObject.prototype.__defineGetter__()Object.prototype.__defineSetter__()Object.prototype.__lookupGetter__()Object.prototype.__lookupSetter__()Object.prototype.hasOwnProperty()Object.prototype.isPrototypeOf()Object.prototype.propertyIsEnumerable()Object.prototype.toLocaleString()Object.prototype.toString()Object.prototype.valueOf()Your blueprint for a better internet.
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