Reprinted from: http: //www.cnblogs.com/xingxiangyi/p/6416468.html
1 array merge
1.1 concat method
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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
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1.2 Loop through
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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']
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1.3 apply
Arr1 merge array and array arr2, using Array.prototype.push.apply (arr1, arr2) or arr1.push.apply (arr1, arr2);
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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']
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2 objects merge
2.1 $.extend()
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var
obj1= {
'a'
: 1};
var
obj2= {
'b'
: 1};
var
c = $.extend(obj1, obj2);
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console.log(obj1);
// {a: 1, b: 1} obj1已被修改
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//或者 <br>var obj3 = $.extend({}, obj1, obj2) <br>console.log(obj3); //{a: 1, b: 1} 不会改变obj1,obj2
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2.2 traversing assignment
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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};
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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)
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//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
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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。
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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 深拷贝
var obj1={'a':1}; var obj2={'b':{'b1':22,'b2':33}}; $.extend(true,obj1, obj2); //第一个参数设为true表示深复制 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) // 22 obj1拷贝了obj2的所有属性以及值,并不受obj2的影响