1、數組的複製
var a = [1,2,3];
b = a.concat(); //b稱爲a的複本
a[3]=4;
a; //[1,2,3,4]
b; //[1,2,3]
/* 另一種ES6寫法,使用了擴展語法 */
var a = [1,2,3];
b = [...a]; //b稱爲a的複本
a[3]=4;
a; //[1,2,3,4]
b; //[1,2,3]
2、Object.assign() 對象淺複製
Object.assign( )是ES6語法
function Person(name, age, job){
this.name = name;
this.age = age;
this.job = job;
this.friends = ["Shelby", "Court"];
}
Person.prototype = {
constructor : Person,
sayName : function(){
alert(this.name);
}
}
var person1 = new Person("Nicholas", 29, "Software Engineer");
var person2 = new Person("Greg", 27, "Doctor");
person1.friends.push("Van");
alert(person1.friends); //"Shelby,Count,Van"
alert(person2.friends); //"Shelby,Count"
alert(person1.friends === person2.friends); //false
alert(person1.sayName === person2.sayName); //true
person3 = Object.assign({}, person1);
person1==person3; //false person3 是 person1 的複本
person1.friends==person3.friends; //true 說明 Object.assign() 是淺複製
3、對象深複製 JSON.parse(JSON.stringify(object));
function Person(name, age, job){
this.name = name;
this.age = age;
this.job = job;
this.friends = ["Shelby", "Court"];
}
Person.prototype = {
constructor : Person,
sayName : function(){
alert(this.name);
}
}
var person1 = new Person("Nicholas", 29, "Software Engineer");
var person2 = new Person("Greg", 27, "Doctor");
person1.friends.push("Van");
alert(person1.friends); //"Shelby,Count,Van"
alert(person2.friends); //"Shelby,Count"
alert(person1.friends === person2.friends); //false
alert(person1.sayName === person2.sayName); //true
person3 = JSON.parse(JSON.stringify(person1));;
person1==person3; //false person3 是 person1 的複本
person1.friends==person3.friends; //false 說明 Json.parse(Json.stringify(..)) 是深複製