js 深拷贝

        function typeOf(obj) {
            const toString = Object.prototype.toString
            const map = {
                '[object Boolean]': 'boolean',
                '[object Number]': 'number',
                '[object String]': 'string',
                '[object Function]': 'function',
                '[object Array]': 'array',
                '[object Date]': 'date',
                '[object RegExp]': 'regExp',
                '[object Undefined]': 'undefined',
                '[object Null]': 'null',
                '[object Object]': 'object'
            }
            return map[toString.call(obj)]
        }

        function deepCopy(data) {
            const t = typeOf(data)
            let o
            if (t === 'array') {
                o = []
            } else if (t === 'object') {
                o = {}
            } else {
                return data
            }

            if (t === 'array') {
                for (let i = 0; i < data.length; i++) {
                    o.push(deepCopy(data[i]))
                }
            } else if (t === 'object') {
                for (let i in data) {
                    o[i] = deepCopy(data[i]);
                }
            }
            return o
        }

        let arr = [{name: 'zs',age: 10}, {name: 'ls',age: 11}]
        let arr2 = deepCopy(arr)
        console.log(arr)
        console.log(arr2)
        console.log(arr === arr2) //false