Merged object array jquery

1. array merge

1.1 concat method

var a=[1,2,3],b=[4,5,6];
var c=a.concat(b);
console.log(c);// 1,2,3,4,5,6
console.log(a);// 1,2,3  不改变本身

1.2 Loop through

var arr1=['a','b'];
var arr2=['c','d','e'];
 
for(var i=0;i<arr2.length;i++){
      arr1.push(arr2[i]) 
}
 
console.log(arr1);//['a','b','c','d','e']

1.3 apply

Arr1 merge array and array arr2, using Array.prototype.push.apply (arr1, arr2) or arr1.push.apply (arr1, arr2);

var arr1=['a','b'];
var arr2=['c','d','e'];
 
Array.prototype.push.apply(arr1,arr2);
 
//或者
 
arr1.push.apply(arr1,arr2);<br>console.log(arr1) //['a','b','c','d','e']

2. Object Merge

2.1 $.extend()

var obj1= {'a': 1};
var obj2= {'b': 1};
var c = $.extend(obj1, obj2);
console.log(obj1); // {a: 1, b: 1}  obj1已被修改
//或者 <br>var obj3 = $.extend({}, obj1, obj2) <br>console.log(obj3); //{a: 1, b: 1} 不会改变obj1,obj2

2.2 traversing assignment

var obj1={'a':1};
var obj2={'b':2,'c':3};
for(var key in obj2){
     if(obj2.hasOwnProperty(key)===true){    <br>     //此处hasOwnProperty是判断自有属性，使用 for in 循环遍历对象的属性时，原型链上的所有属性都将被访问会避免原型对象扩展带来的干扰
           obj1[key]=obj2[key];
} 
}
 
console.log(obj1);//{'a':1,'b':2,'c':3};

2.3 Obj.assign()

　It can be any number of source object itself may be enumerated attribute copy to the target object, the target object and then returns.
　　Object.assign (target, ... sources)

//a. 复制一个对象<br>var obj = { a: 1 ,b:2};
var copyObj = Object.assign({}, obj);
console.log(copyObj); // { a: 1,b:2 }<br><br>//b.合并多个对象

var o1 = { a: 1 };
var o2 = { b: 2 };
var o3 = { c: 3 };
 
var obj = Object.assign(o1, o2, o3);
console.log(obj); // { a: 1, b: 2, c: 3 }
console.log(o1);  // { a: 1, b: 2, c: 3 }, 且目标对象自身也会改变。

2.4 deep copy and shallow copy of the object

2.4.1 shallow copy

var obj1={'a':1};
var obj2={'b':{'b1':22,'b2':33}};

$.extend(obj1, obj2);   //obj1拷贝了obj2的属性

console.log(obj1)  // {'a':1,'b'{'b1':22,'b2':33}}
console.log(obj1.b.b1)  // 22

obj2.b.b1=44;   //obj2重新赋值
console.log(obj1.b.b1)  // 44  obj1.b仅拷贝了对象的指引，所以受原obj2的影响

2.4.2 deep copy

var obj1={'a':1};
var obj2={'b':{'b1':22,'b2':33}};

$.extend(obj1, obj2);   //obj1拷贝了obj2的属性

console.log(obj1)  // {'a':1,'b'{'b1':22,'b2':33}}
console.log(obj1.b.b1)  // 22

obj2.b.b1=44;   //obj2重新赋值
console.log(obj1.b.b1)  // 44  obj1.b仅拷贝了对象的指引，所以受原obj2的影响