The Javascript Function.length property of the function object in Javascript is used to return the number of parameters required by a function.
Syntax:
function.length
Parameters: This method requires no parameters.
Return: Return type is number.
A few examples are given below for a better understanding of the method.
Example 1: When the number of parameters is zero.
Javascript
<script> // Creating function name func // When no parameters are given function func1(){} console.log( "The number of parameters required by " + "the function are: " , func1.length) </script> |
Output:
The number of parameters required by the function are: 0
Example 2: When the number of parameters is greater than one.
Javascript
<script> // Creating function name func // When one parameters are given function func1(a){} console.log( "The number of parameters required by the func1 are: " , func1.length) // When two parameters are given function func2(a, b){} console.log( "The number of parameters required by the func2 are: " , func2.length) // When three parameters are given function func3(a, b, c){} console.log( "The number of parameters required by the func3 are: " , func3.length) // When four parameters are given function func4(a, b, c, d){} console.log( "The number of parameters required by the func4 are: " , func4.length) </script> |
Output:
The number of parameters required by the func1 are: 1 The number of parameters required by the func2 are: 2 The number of parameters required by the func3 are: 3 The number of parameters required by the func4 are: 4
Example 3: When an array of arguments is given
Javascript
<script> // Creating function name func // When array of arguments are given function func4(...args){} console.log( "The number of parameters required by the func4 are: " , func4.length) </script> |
Output:
The number of parameters required by the func4 are: 0
We have a complete list of Javascript Function methods, to check those please go through this Javascript Function Complete reference article.
Supported Browser:
- Chrome 1 and above
- Edge 12 and above
- Firefox 1 and above
- Internet Explorer 4 and above
- Opera 3 and above
- Safari 1 and above