@stdlib/utils-function-name NPM

Function Name

Determine a function's name.

Installation

npm install @stdlib/utils-function-name

Usage

var functionName = require( '@stdlib/utils-function-name' );

functionName( fcn )

Returns the name of a function.

var v = functionName( Math.sqrt );
// returns 'sqrt'

If provided an anonymous function, the function returns an empty string or the string "anonymous".

var v = functionName( function () {} );
// returns '' || 'anonymous'

If provided a value which is not a function, the function throws a TypeError.

try {
    functionName( 'beep' );
    // throws error...
} catch ( err ) {
    console.error( err );
}

Notes

For more information regarding the naming of anonymous functions, see
- Function Names in ES6
- Webkit bug 7726
- MDN

Examples

var Float64Array = require( '@stdlib/array-float64' );
var Buffer = require( '@stdlib/buffer-ctor' );
var Number = require( '@stdlib/number-ctor' );
var Boolean = require( '@stdlib/boolean-ctor' );
var Function = require( '@stdlib/function-ctor' );
var functionName = require( '@stdlib/utils-function-name' );

var v = functionName( Math.sqrt );
// returns 'sqrt'

v = functionName( Float64Array );
// returns 'Float64Array'

v = functionName( Buffer );
// returns 'Buffer'

v = functionName( Date );
// returns 'Date'

v = functionName( String );
// returns 'String'

v = functionName( Boolean );
// returns 'Boolean'

v = functionName( Function );
// returns 'Function'

v = functionName( Number );
// returns 'Number'

v = functionName( function foo() {} );
// returns 'foo'

v = functionName( function () {} );
// returns '' || 'anonymous'

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.