Parasitic Constructor Pattern
Description
The parasitic constructor pattern is to create a constructor that simply wraps the creation and return of another object.
Example
function Person(name, age, job){// www . j ava2 s. co m
var o = new Object();
o.name = name;
o.age = age;
o.job = job;
o.sayName = function(){
console.log(this.name);
};
return o;
}
var friend = new Person("XML", 29, "markup");
friend.sayName(); //"XML"
The code above generates the following result.
Note
The function is called as a constructor, using the new operator.
Example 2
You create a special array that has an extra method.
function MyArray(){/* w ww.j av a 2s. c o m*/
var values = new Array();
values.push.apply(values, arguments);
values.toMyString = function(){
return "["+this.join(",")+"]";
};
values.count = function(){
return this.length;
};
return values;
}
var colors = new MyArray("A", "B", "C");
console.log(colors.toMyString());
console.log(colors.count());
The code above generates the following result.
