The arguments.length
data property contains the number of arguments passed to the function.
The arguments.length
data property contains the number of arguments passed to the function.
A non-negative integer.
Property attributes of arguments.length
| |
---|---|
Writable | yes |
Enumerable | no |
Configurable | yes |
The arguments.length
property provides the number of arguments actually passed to a function. This can be more or less than the defined parameter's count (see Function.prototype.length
). For example, for the function below:
function func1(a, b, c) { console.log(arguments.length); }
func1.length
returns 3
, because func1
declares three formal parameters. However, func1(1, 2, 3, 4, 5)
logs 5
, because func1
was called with five arguments. Similarly, func1(1)
logs 1
, because func1
was called with one argument.
In this example, we define a function that can add two or more numbers together.
function adder(base /*, num1, …, numN */) { base = Number(base); for (let i = 1; i < arguments.length; i++) { base += Number(arguments[i]); } return base; }
Desktop | Mobile | Server | ||||||||||||
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Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | Deno | Node.js | ||
length |
1 | 12 | 1 | 4 | 1 | 18 | 4 | 10.1 | 1 | 1.0 | 4.4 | 1.0 | 0.10.0 |
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/arguments/length