quincy-type-is

A small library of predicate functions for JavaScript value types.

Install

To install for your project:

npm install --save-dev quincy-type-is

Then use the module:

var type = require('quincy-type-is');

API

type

type(value)

Returns a value's type as a string using Object.prototype.toString

type('name') //=> '[object String]'

Constants are available for the following:

• type.ARGS (arguments object);
• type.ARRAY
• type.DATE
• type.FUNCTION
• type.OBJECT
• type.NUMBER
• type.REGEX
• type.STRING
• type.UNDEF
• type.NULL

type('name') === type.STRING

isSome

isSome(value)

Returns true if the value is something other than undefined or null or false if it is either undefined or null

    var x;
    isSome(x); // => false
    isSome('name'); // => true

isNone

isNone(value)

Returns true if the value is undefined or null or false otherwise.

    var x;
    isNone(x); // => true
    isNone('name'); // => false

isUndef

isUndef(value)

Returns true if the value is undefined or false otherwise.

    var x;
    isUndef(x); // => true

isNull

isNull(value)

Returns true if the value is null or false otherwise.

    var x;
    var y = null;
    isNull(x); // => false
    isNull(y); // => true

isArray

isArray(value)

Returns true if the value is an Array or falseotherwise.

isArray([]); // => true

isFunction

isFunction(value)

Returns true if the value is a function or false otherwise.

isFunction({}); // => false
isFunction(function() {}); // => true

isObject

isObject(value)

Returns true if the value is a plain Object or false otherwise.

isObject({}); // => false
isObject(function() {}); // => false

isRegExp

isRegExp(value)

Returns true if the value is a RegExp or false otherwise.

isRegExp(/foo/); // => true

isString

isString(value)

Returns true if the value is a string or false otherwise.

isString('a'); // => true

isNumber

isNumber(value)

Returns true if the value is a number or false otherwise.

isNaN

isNaN(value)

Returns true if the value is NaN or false otherwise. This implementation circumvents the coercion done by the global isNaN.

isNaN(2); // => false
isNaN(''); // => false

isDate

isDate(value)

Retuns true if the value is a Date value or false otherwise.

isDate(new Date()); // => true

isIterable

isIterable(value)

Returns true if the value is an Array or an array-like object with a length property.

isIterable([]); // => true