js變數型別判斷 嚴格通用 Object.prototype.toString.call()
阿新 • • 發佈:2018-11-21
Object.prototype.toString.call()判斷結果:
Object.prototype.toString.call(true) "[object Boolean]" Object.prototype.toString.call(1) "[object Number]" Object.prototype.toString.call(null) "[object Null]" Object.prototype.toString.call(undefined) "[object Undefined]" Object.prototype.toString.call('ndefined') "[object String]" Object.prototype.toString.call([]) "[object Array]" Object.prototype.toString.call({}) "[object Object]" Object.prototype.toString.call(alert) "[object Function]"
typeof判斷結果:
typeof undefined
"undefined"
typeof true
"boolean"
typeof 1
"number"
typeof 'sds'
"string"
typeof alert
"function"
typeof null
"object"
typeof []
"object"
typeof {}
"object"