Discussion on js deep copy examples

Deep copy is a copy that copies the parent object to the child object, and the memory and subsequent operations of the two do not affect each other. This article mainly shares with you the discussion of js deep copy examples, hoping to help everyone.

(1) Method 1

function copy(obj1,obj2){
  var obj2=obj2||{}; 
  for(var name in obj1){    if(typeof obj1[name] === "object"){ //先判断一下obj[name]是不是一个对象
      obj2[name]= (obj1[name].constructor===Array)?[]:{}; 
      copy(obj1[name],obj2[name]); //然后来无限递归
    }else{
      obj2[name]=obj1[name];  //如果不是对象，直接赋值。
    }
  }  return obj2; 
}

Usage method:

var obj1 = {
    se:[{a:1,b:2},{c:3}],
    sa:{a:"g"},
    sc:function(){console.log(1)}
}var n_obj = copy(obj1,{})
console.log(n_obj)

(2) Method 2

function d_clone(obj) {
    return Object.getPrototypeOf(Object.create(obj));
}

Usage method:

var obj1 = {
    se:[{a:1,b:2},{c:3}],
    sa:{a:"g"},
    sc:function(){console.log(1)}
}var n2_obj = d_clone(obj1);
console.log(n2_obj)

(3) Method 3

JSON.parse(JSON.stringify(obj)

Description: The attributes of obj cannot contain functions.

(1) Method 1

function copy(obj1,obj2){
  var obj2=obj2||{}; 
  for(var name in obj1){    if(typeof obj1[name] === "object"){ //先判断一下obj[name]是不是一个对象
      obj2[name]= (obj1[name].constructor===Array)?[]:{}; 
      copy(obj1[name],obj2[name]); //然后来无限递归
    }else{
      obj2[name]=obj1[name];  //如果不是对象，直接赋值。
    }
  }  return obj2; 
}

Usage method:

var obj1 = {
    se:[{a:1,b:2},{c:3}],
    sa:{a:"g"},
    sc:function(){console.log(1)}
}var n_obj = copy(obj1,{})
console.log(n_obj)

(2) Method 2

function d_clone(obj) {
    return Object.getPrototypeOf(Object.create(obj));
}

Usage method:

var obj1 = {
    se:[{a:1,b:2},{c:3}],
    sa:{a:"g"},
    sc:function(){console.log(1)}
}var n2_obj = d_clone(obj1);
console.log(n2_obj)

(3) Method 3

JSON.parse(JSON.stringify(obj)

Description: The attributes of obj cannot contain functions.

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