Factory mode
Creates and returns a specific type of object.
Copy Code code as follows:
function Createcar (scolor,idoors,impg) {
var otempcar=new Object ();
Otempcar.color=scolor;
Otempcar.doors=idoors;
Otempcar.mpg=impg;
Otempcar.showcolor=function () {
alert (This.color);
}
return otempcar;
}
Call Example:
Copy Code code as follows:
var ocar1=createcar ("Red", 4,23);
var ocar2=createcar ("Blue", 3,25);
Ocar1.showcolor ();
Ocar2.showcolor ();
Disadvantage: Methods are created repeatedly. As in the previous invocation example, both OCAR1 and OCar2 have their own shocolor methods, but this can be shared.
Constructor method
Example:
Copy Code code as follows:
function car (scolor,idoors,impg) {
This.color=scolor;
This.door=idoors;
This.mpg=impg;
This.showcolor=function () {
alert (This.color);
}
}
Call Example:
Copy Code code as follows:
var ocar1=new car ("Red", 4,23);
var ocar2=new car ("Blue", 3,25);
Disadvantage: As with the factory approach, methods are created repeatedly.
prototype Mode
This method utilizes the prototype attribute of an object, which can be viewed as the prototype on which the new object is created. This uses an empty constructor to set the class name, and then all the properties and methods are given directly to the prototype property, overriding the previous example with the following code:
Copy Code code as follows:
function car () {
}
Car.prototype.color= "Red";
car.prototype.doors=4;
car.prototype.mpg=23;
Car.prototype.showcolor=function () {
alert (This.color);
}
Call:
Copy Code code as follows:
var ocar1=new car ();
var ocar2=new car ();
Disadvantage: The value of the parameter initialization property cannot be passed to the constructor
Mixed constructor/prototype approach
Use constructors and prototypes in conjunction with the following example:
Copy Code code as follows:
function car (scolor,idoors,impg) {
This.color=scolor;
This.door=idoors;
This.mpg=impg;
}
Car.prototype.showcolor=function () {
alert (This.color);
}
Call Example:
Copy Code code as follows:
var ocar1=new car ("Red", 4,23);
var ocar2=new car ("Blue", 3,25);
Advantages: No memory waste, easy to create.
This approach is the main method used by ECMAScript.
Dynamic Prototyping Method
Using a mixed constructor/prototyping method to place the object's methods outside of the object definition, which makes people feel less object-oriented and not visually well encapsulated, creates a dynamic prototyping method:
Copy Code code as follows:
function car (scolor,idoors,impg) {
This.color=scolor;
This.door=idoors;
This.mpg=impg;
if (typeof car._initialized== "undefined") {
Car.prototype.showcolor=function () {
alert (This.color);
};
Car._initialized=true;
}
}
Author: artwl
Source: http://artwl.cnblogs.com
