typist

typist provides a reliable typeOf function for javascript's primitive types.

usage

<script src="typist.js"></script>

then:

var t = window.typist;

// -> 'number'
t.typeOf(1234);

or as a node package:

npm install typist

then:

var t = require('typist');

// -> 'boolean'
t.typeOf(true);

api

typeOf(item)

Returns the primitive type of item. 
If item is not a 'string', 'number', 'boolean', 'array', or 'function', return 'object'.

isString(item)

Return true if the item is a string.

isNumber(item)

Return true if the item is a number.

isBoolean(item)

Return true if the item is a boolean.

isArray(item)

Return true if the item is an array.

isFunction(item)

Return true if the item is a function.

isObject(item)

Return true if the item is an object. 
`isObject` will return false if the item is another primitive type.

buildIsType(type, constructor)

To build an 'isType' function for any type, use buildIsType.
We can build one for typed arrays of 8 bit signed integers.

var isInt8Array = buildIsType('Int8Array', Int8Array);

The first argument is the name of the type as a string.
It is used to build to string returned by the call to

Object.prototype.toString.call(item);

The case of the type string is corrected automatically.

'Int8Array' becomes '[object Int8Array]'
'int8Array' becomes '[object Int8Array]'

The second argument is the constructor function of the type.

As another example, we can construct any of the primitive type
identifying functions.

var isNumber = buildIsType('number', Number);
var isArray = buildIsType('array', Array);
 
These constructed versions are less efficient than the ones provided
below since the type operator will never succeed (the types you construct 
will assume that `typeof yourObj` returns 'object').
    

tests

Execute npm test to run typist's unit tests.