typist

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

usage

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.