判断类型及深拷贝

function judgeTypeFnCreator (type) {

const toString = Object.prototype.toString

return function isType (o) {

return toString.call(o) === `[object ${type}]`

}

}

 

 

const isFunc = judgeTypeFnCreator('Function')

const isUndef = judgeTypeFnCreator('Undefined')

const isArray = judgeTypeFnCreator('Array')

const isString = judgeTypeFnCreator('String')

const isObject = judgeTypeFnCreator('Object')

const isNumber = judgeTypeFnCreator('Number')

 

 

function deepAssign(to, from) {

for (let key in from) {

if (!to[key] || typeof to[key] !== 'object') {

to[key] = from[key]

} else {

deepAssign(to[key], from[key])

}

}

}