2021-09-29

new Date()

• new Date()获取到的是系统时间，以服务器时间为准。

类型判断

var data = "";//获取数据的类型
var type = Object.prototype.toString.call(data).slice(8,-1);

instanceof 对象

let a = {}

a instanceof Array
// false
a instanceof Object
// true
数组

[] instanceof Array
// true
[] instanceof Object
// true

类型	公式	结果
[]	typeof []	"object"
{}	typeof {}	"object"
""	typeof ""	"string"
null	typeof null	"object"
NaN	typeof NaN	"number"
0	typeof 0	"number"
1	typeof 1	"number"
"function"	typeof Object	"function"
function a(){console.log(1)}	typeof a	"function"
function a(){console.log(1)}	typeof a()	"undefined"
cccc	typeof cccc	"undefined"
false	typeof false	"boolean"
true	typeof true	"boolean"