The Javascript Function Constructor is used to create a new function object using the Function() constructor with the new operator. The Javascript Function Constructor creates a function that has a global scope.
Syntax:
var variable = new Function(arg1, arg2..., Function Body)
Parameters:
- arg*: It is an optional parameter. A function can contain any number of string arguments.
- Function Body: It is an argument that contains the Javascript statements containing the function definition.
Below are some examples that show the use of the Javascript function constructor.
Example 1: In this example, we will see the basic use of the Javascript function constructor.
HTML
<!DOCTYPE HTML> < html > < head > < script type = "text/javascript" > <!-- var func = new Function("x", "y", "return x*y;"); function neveropen() { var result; result = func(10,20); document.write ( result ); } </ script > </ head > < body > < h1 style = "color:green" > Geeks For Geeks </ h1 > < h3 >Javascript function constructor</ h3 > < p >Click the following button to see the result</ p > < input type = "button" onclick = "neveropen()" value = "Click Me" > </ body > </ html > |
Output:
Example 2: In this example, we will create a Javascript constructor and print the values of the function.
HTML
<!DOCTYPE HTML> < html > < head > < script type = "text/javascript" > <!-- var func = new Function("firstName", "lastName", "return firstName + ' ' + lastName + ' ' + firstName;"); function neveropen() { var result; result = func("Geeks","for"); document.write ( result ); } </ script > </ head > < body > < h1 style = "color:green" > Geeks For Geeks </ h1 > < h3 >Javascript function constructor</ h3 > < p >Click the following button to see the result</ p > < input type = "button" onclick = "neveropen()" value = "Click Me" > </ body > </ html > |
Output:
We have a complete list of Javascript Functions, to check those please go through this Javascript Function Complete reference article.