Four Methods for defining javascript classes

Copy codeThe Code is as follows:
/*
Factory method --- create and return the factory function of a specific type of object)
*/
Function createCar (color, doors, mpg ){
Var tempCar = new Object;
TempCar. color = color;
TempCar. doors = doors;
TempCar. mpg = mpg;
TempCar. showCar = function (){
Alert (this. color + "" + this. doors );
}
Return tempCar;
}

/*
Constructor method --- constructor looks like a factory function
*/
Function Car (color, doors, mpg ){
This. color = color;
This. doors = doors;
This. mpg = mpg;
This. showCar = function (){
Alert (this. color );
};
}
/*
Prototype Method-the prototype attribute of an object can be used to create a prototype on which the object depends.
*/
Function Car (color, doors, mpg ){
This. color = color;
This. doors = doors;
This. mpg = mpg;
This. drivers = new Array ("nomad", "angel ");
}

Car. prototype. showCar3 = function (){
Alert (this. color );
};

/*
Hybrid constructor/prototype-use constructor to define all non-function attributes of an object, and use prototype to define function attributes (methods) of an object)
*/
Function Car (sColor, iDoors, iMpg ){
This. color = sColor;
This. doors = iDoors;
This. mpg = iMpg;
This. drivers = new Array ("Mike", "Sue ");
}

Car. prototype. showColor = function (){
Alert (this. color );
};
/*
Dynamic Prototype Method-non-function attributes are defined in the constructor, while function attributes are defined using the prototype attributes. The only difference is that the location of the object method is assigned.
*/
Function Car (sColor, iDoors, iMpg ){
This. color = sColor;
This. doors = iDoors;
This. mpg = iMpg;
This. drivers = new Array ("Mike", "Sue ");

If (typeof Car. _ initialized = "undefined "){

Car. prototype. showColor = function (){
Alert (this. color );
};

Car. _ initialized = true;
}
} // This method uses the sign (_ initialized) to determine whether any method has been granted to the prototype.