深拷贝 实现

//1. 判断数据的类型
function checkType(target){
    return Object.prototype.toString.call(target).slice(8,-1)
}

//2.定义拷贝函数
function clone(target){
    let result,targetType =checkType(target);
    if( targetType===‘Object‘){
        result = {};
    }else if(targetType ==="Array"){
        result = [];
    }else{
        return target;
    }
    //遍历数据结构中的每一项值
    for(let i in target){
        let value = target[i]
        if(checkType(value)===‘Object‘ || checkType(value)===‘Arrary‘){
            //继续遍历获取到的值
            clone(value)
        }else{
            result=value
        }
    }
    return result;
}