实现对象的深拷贝

function deepCopy(data) {
    let typeOf = function(data) {
        const toString = Object.prototype.toString;
        const map = {
            '[object Array]': 'array', 
            '[object Boolean]':'boolean',
            '[object Object]':'object',
            '[object Number]':'number',
            '[object Function]': 'function',
            '[object String]': 'string',
            '[object RegExp]': 'regExp',
            '[object Data]': 'date',
            '[object Undefined]': 'undefined',
            '[object Null]': 'null',
            
        }
        return map[toString.call(data)]
    }
   
    const t = typeOf(data);//拿到数据的类型
    let result;
    if (t === 'array') {//数组
        result = [];
        for (let i = 0; i < data.length; i++){
            result.push(deepCopy(data[i]))
        }
    } else if (t === 'object') {//对象
        result = {};
        for (let key in data) {
            result[key] = deepCopy(data[key])
        }
    } else {
        return data
    }
    return result;
}