stdlib-js
<summary>
About stdlib...
</summary>
We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.
The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.
When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.
To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!
Function
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
[Function][mdn-function] constructor.
bash
npm install @stdlib/function-ctor
javascript
var Function = require( '@stdlib/function-ctor' );
#### Function( [...argNames,] body )
Returns a new [function][mdn-function] object.
javascript
var greet = new Function( 'name', 'return "Hello, "+name+"!"' );
var v = greet( 'Jane' );
// returns 'Hello, Jane!'
Argument names must be strings corresponding to valid JavaScript parameters (i.e., a plain identifier, or, in environments supporting such parameters, a rest parameter or destructured parameter, optionally with a default).
### Properties
#### Function.prototype.length
A number representing the number of arguments expected by the function.
javascript
var greet = new Function( 'name', 'return "Hello, "+name+"!"' );
var v = greet.length;
// returns 1
#### Function.prototype.name
Read-only property representing the name of the function.
javascript
function greet( name ) {
return 'Hello, '+name+'!';
}
var v = greet.name;
// returns 'greet'
// Functions created with the Function constructor are anonymous:
var fcn = new Function( 'name', 'return "Hello, "+name+"!"' );
v = fcn.name;
// returns 'anonymous'
#### Function.prototype.prototype
Read-only property representing the prototype of the function.
javascript
function greet( name ) {
return 'Hello, '+name+'!';
}
var proto = greet.prototype;
// returns {}
### Methods
#### Function.prototype.apply( thisArg, args )
Calls the specified function with the given this argument and arguments provided as an array-like object.
javascript
function add( x, y ) {
return this.initial + x + y;
}
var ctx = {
'initial': 10
};
var v = add.apply( ctx, [ 1, 2 ] );
// returns 13
#### Function.prototype.bind( thisArg[, arg1[, arg2[, ...]]] )
Returns a new function which invokes the original function with the given this value and arguments.
javascript
function add( x, y ) {
return x + y;
}
var add1 = add.bind( null, 1 );
var v = add1( 2 );
// returns 3
#### Function.prototype.call( thisArg[, arg1[, arg2[, ...]]] )
Calls the specified function with the given this value and arguments.
javascript
function add( x, y ) {
return this.initial + x + y;
}
var ctx = {
'initial': 10
};
var v = add.call( ctx, 1, 2 );
// returns 13
#### Function.prototype.toString()
Returns a string representing the function.
javascript
function add( x, y ) {
return x + y;
}
var v = add.toString();
// e.g., returns 'function add( x, y ) {\n return x + y;\n}'
Function objects with the Function constructor is less efficient than declaring a function via a function expression or a function statement.
- The Function constructor can be invoked without the new operator (using new and not using new both return a new Function object).
- The Function constructor creates functions which execute in the global scope. Hence, created functions cannot access variables local to the scope in which functions were created.javascript
var Function = require( '@stdlib/function-ctor' );
var add = new Function( 'x', 'y', 'return x + y' );
var v = add( 1, 2 );
// returns 3
