JS基礎——資料型別判斷typeof、instanceof、Object.prototype.toString
摘要:
typeof
instanceof
Object.prototype.toString
對應測試結果如下:
typeof test
instanceof
...
typeof instanceof Object.prototype.toString
對應測試結果如下:
typeof test
|
instanceof
|
Object.prototype.toString.call(test)
|
|
var test = 'xuriliang'; | string |
test instanceof String//false
|
[object String] |
var test = 27; | number |
test instanceof Number//false
|
[object Number] |
var test = true; | boolean |
test instanceof Boolean//false
|
[object Boolean] |
var test = [1,2,3]; | object |
test instanceof Array//true
|
[object Array] |
test instanceof Object//true
|
|||
var test = null; | object |
test instanceof Object//false
|
[object Null] |
var test = undefined; | undefined |
test instanceof Object//false
|
[object Undefined] |
var test = new String('xuriliang') | object |
test instanceof String//true
|
[object String] |
test instanceof Object//true
|
|||
var test = new Number(27) | object |
test instanceof Number//true
|
[object Number] |
test instanceof Object//true
|
|||
var test = new Boolean(true) | object |
test instanceof Boolean//true
|
[object Boolean] |
test instanceof Object//true
|
|||
var test = new Array(1,2,3) | object |
test instanceof Array//true
|
[object Array] |
test instanceof Object//true
|
|||
var test = function(){} | function |
test instanceof Function//true
|
[object Function] |
test instanceof Object//true
|
|||
var test = /d/ | object |
test instanceof RegExp//true
|
[object RegExp] |
test instanceof Object//true
|