对象的深拷贝

function deepCopy(data){
	if(data instanceof Array){
		let ary=[];
		for(let i=0;i<data.length;i++){
			ary[i]=deepCopy(data[i]);
		}
		return ary;
	}else if(data instanceof Object){
		let obj={};
		for(let attr in data){
			obj[attr]=deepCopy(data[attr]);
		}
		return obj;
	}else{
		return data;
	}
}