js通过一个方法实现对象的深浅拷贝。

Posted 2020-09-30 未来-竭尽全力

众所周知，对象的深浅拷贝是工作中肯定会遇到的问题。所以，今天考虑写个小的功能来记录一下

//type:boolean,true-deep,true为深拷贝，
function extendCopy(type,item){
  if(typeof type != "boolean" || typeof item !=‘object‘){
     return  
  }
var newObj = item.constructor ==="Array" ?[]:{};
  if(type){
     if(window.JSON){
          return JSON.parse(JSON.stringify(item));
     }  
     else{
        for(prop in item){
           if(getType(item[prop]) ==‘array‘ ||           getType(item[prop]==“object”)){
             newObj[prop]= extendCopy(type,item[prop]);
          }
          else{
             newObj[prop] = item[prop];
          }     
        }
     }  

 }    
else{
for (prop in item){
newObj[prop] = item[prop];
}
return newObj;

}

}

//实现js内置类型的检测
function getType(o){
      var _toString=Object.prototype.toString;
      var _type={
                 "undefined":"undefined",
                 "number":"number",
                 "boolean":"boolean",
                 "string":"string",
                 "[object Function]":"function",
                 "[object Array]":"array",
                 "[object RegExp]":"regexp",
                 "[object Date]":"date",
                 "[object Erroe]":"error"
        }
        return _type[typeof o]||_type[_toString.call(o)]||(o?"object":"null");
}