JavaScript defines an object's methods

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Http://news.sohu.com/20110215/n279335637.shtml?

Some simple ways to define a JavaScript object

1. Constructor mode, all properties and methods of the object are defined in the constructor method.

Advantages: Dynamic Transfer of parameters

Cons: Every object created will create the same method function object, consuming a lot of memory

function User1 (name, password) {
THIS.name = name;
This.password = password;
This.login = function (Name,password) {
  if (this.name = = Name && This.password = = password) {
   return true;
  }else {
   return false;
  }
};
}

2. Prototype mode, the object properties and method definitions are written in the object's prototype inside

Pros: Every time you create an object, you use the same method in the same prototype, without consuming duplicate memory

Cons: Unable to dynamically pass construction parameters

function User2 () {

}
User2.prototype.name = "prototype name";
User2.prototype.password = "Prototype password";
User2.prototype.login = function (Name,password) {
if (this.name = = Name && This.password = = password) {
return true;
} else {
return false;
}
};
Another way of prototyping:
Format:
var object name = {};
Object name. prototype. Variable 1 = value of variable 1;
Object name. prototype. variable 2 = value of variable 2;
......;
Object name. prototype. function 1= functions () {
function body
};
Object name. prototype. function 2= functions () {
function body
};
......;
Description
(1) The initial object body may not define anything;
(2) Add "object name. Prototype" before the variable to be defined. The format;
(3) The content and value of the object are separated by an equal sign and appear in pairs;
(4) The included variables or functions are separated by semicolons, or you can omit semicolons.
(5) The function needs to be written inside the curly braces of functions () {}.
Example:
var data = {};
Data.prototype. Name = "Vicky";
Data.prototype. Age = 20;
Data.prototype. Eat = function () {
Alert (' I wanna Eat meat ');
};
Data.prototype. sleep= function () {
Alert (' I wanna Sleep ');

};

3. Construction and prototype blending method, write the attribute definition in the construction mode, the method is written in prototype

Advantages: Combining the advantages of the construct and prototype modes, you can dynamically transfer the construction parameters, and the method function object creates only one

Cons: Functions are written outside of the object and are not quite consistent with object-oriented thinking

function User3 (Name,password) {
THIS.name = name;
This.password = password;
}
User3.prototype.login = function (Name,password) {
if (this.name = = Name && This.password = = password) {
  return true;
} else {
  return false;
}
};

4. Dynamic Prototyping method: Add a Judgment attribute to determine whether the object has been created, if it was created, then the method is not built

Advantage: Write the prototype function inside the object definition

Cons: Inheritance is not supported

function User4 (Name,password) {
THIS.name = name;
This.password = password;
if (typeof user4.__initialized = = "undefined") {
  User4.prototype.login = function (Name,password) {
   if (this.name = = Name && This.password = = password) {
    return true;
   } else {
    return false;
   }
  };
  User4.__initialized = true;
}
}

5. JSON mode/Object Direct volume

Format:
var object name = {
Variable 1: The value of variable 1,
Variable 1: The value of variable 1,
......,
function 1:function () {
function body
},
function 2:function () {
function body
}//note: The last comma to be removed in order to be compatible with IE.
};
Description
(1) A variable or function is directly filled in curly braces;
(2) The contents and values of the object are separated by colons and appear in pairs;
(3) The variables or functions included are separated by commas;
(4) The function needs to be written inside the curly braces of functions () {}.
Example:
var object name = {
Name: "Vicky",
Age:26,
Eat:function () {
Alert (' I wanna Eat meat ');
},
Sleep:function () {
Alert (' I wanna Sleep ');
}
};
Note: A similar approach is called anonymous class
Anonymous class Examples:
{
Index: '//',
Reg:new RegExp (' ^//.*$ '),
CSS: "comment"
}
The above method creates a class, but does not assign a variable to it.

6. Create mode

This approach leverages the prototype JavaScript component library.
Format:
var object name = Class.create ();
Object.extend (object name. prototype, {
Variable 1: The value of variable 1,
Variable 1: The value of variable 1,
......,
function 1:function () {
function body
},
function 2:function () {
function body
},
......
});
Description
(1) The object is created using the Class.create () function in the prototype library;
(2) The content of the object is extended using the Object.extend () function in the prototype library;
(3) The extended object must take prototype when passing in the Object.extend function.
(4) The extension content is enclosed in curly braces, which is exactly the same as the JSON-defined format.
Example:
var data = Class.create ();
Object.extend (Dta.prototype, {
Name: "Vicky",
AGE:20,
Eat:function () {
Alert (' I wanna Eat meat ');
},
Sleep:function () {
Alert (' I wanna Sleep ');
}
});

In fact, the definition of JS objects There are other ways, you can also use the above several combinations of definitions, which shows that JS as a dynamic language of freedom.
The normal way to create a JS object is as follows:
var D1 = new Data ();
There are two ways to refer to a JS object variable:
(1) Point number method reference, such as, Data.name.
(2) array mode reference, e.g., data[' name '].

JavaScript defines an object's methods