JS 浅拷贝与深拷贝

1.浅拷贝(引用类型的复制都是浅拷贝)

var arr1 = [1,2,3,4];
arr2 = arr1;
arr2.push(5);
console.log(arr1);//[1,2,3,4,5]

2.对象的浅拷贝

function copy(obj){
  var tempObj = {};
  for(var i in obj){
    tempObj[i] = obj[i]; //属性复制
  }
  return tempObj
}
var Person = {
  name:'person',
  skills:['g','s','m']
}
var newPerson = copy(Person);
console.log(Person.skills ) ;//['g','s','m'];
newPerson.skills.push('b');
console.log(Person.skills); // ['g','s','m','b']; 浅拷贝,只是拷贝了指向引用类型的地址
console.log(newPerson .skills); // ['g','s','m','b']; 

2.对象的深拷贝(在浅拷贝的基础上递归调用)

function deepCopy(obj, newObj) {
　　var tempObj= newObj || {};
　　for (var i in obj) {
　　　　if (typeof obj[i] === 'object') {
　　　　　　tempObj[i] = (obj[i].constructor === Array) ? [] : {};
　　　　　　deepCopy(obj[i], tempObj[i]);
　　　　} else {
　　　　　　tempObj[i] = obj[i];
　　　　}
　　}
　　return tempObj;
};
var Person = {
  name:'person',
  skills:['g','s','m']
}
var newPerson = deepCopy(Person);
console.log(Person.skills ) ;//['g','s','m'];
newPerson.skills.push('b');
console.log(Person.skills); // ['g','s','m']; 
console.log(newPerson .skills); // ['g','s','m','b'];