@stdlib/assert-is-method-in NPM

isMethodIn

Test if an object has a specified method name, either own or inherited.

Installation

npm install @stdlib/assert-is-method-in

Usage

var isMethodIn = require( '@stdlib/assert-is-method-in' );

isMethodIn( value, property )

Returns a boolean indicating if a value has a specified method name, either own or inherited.

var value = {
    'beep': 'boop'
};

var bool = isMethodIn( value, 'toString' );
// returns true

bool = isMethodIn( value, 'beep' );
// returns false

bool = isMethodIn( value, 'bap' );
// returns false

Notes

The function does not throw when provided null or undefined. Instead, the function returns false.

var bool = isMethodIn( null, 'toString' );
// returns false

bool = isMethodIn( void 0, 'toString' );
// returns false

Value arguments other than null or undefined are coerced to objects.
```
var bool = isMethodIn( 'beep', 'toString' );
// returns true
```

Non-symbol property arguments are coerced to strings.

function noop() {
    // Example function...
}

var value = {
    'null': noop
};
var bool = isMethodIn( value, null );
// returns true

value = {
    '[object Object]': noop
};
bool = isMethodIn( value, {} );
// returns true

Examples

var isMethodIn = require( '@stdlib/assert-is-method-in' );

var bool = isMethodIn( {}, 'toString' );
// returns true

bool = isMethodIn( { 'a': 'b' }, 'a' );
// returns false

bool = isMethodIn( { 'a': 'b' }, 'c' );
// returns false

bool = isMethodIn( { 'a': 'b' }, null );
// returns false

bool = isMethodIn( null, 'a' );
// returns false

bool = isMethodIn( void 0, 'a' );
// returns false

bool = isMethodIn( { 'null': isMethodIn }, null );
// returns true

bool = isMethodIn( { '[object Object]': isMethodIn }, {} );
// returns true

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.