this is an exmaple.
var x=5;
var y=x.multiplied(6); // return y=30;
how to create a function like .multiplied() function on js?
the function structure is like this
var1.doSomething(var2);
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3 Answers
function myInteger( setVal ) {
this.value = setVal;
}
myInteger.prototype.multiple( mult ) {
return this.value * mult;
// Or
// return new myInteger( this.value * mult );
}
var x = new myInteger(5)
var y = x.multiple(6);
3 Comments
theHack
do i have to specify the variable like this ar x = new myInteger(5)? can't i just specify var=5; like another js function?...
SergeS
if you specify it like var foo = 5; it will use built-in type integer( and AFAIK there is no way to bind function to integer ) - so only solution is to create own prototypes - objects, made exactly by your needs
stecb
you CAN extend built-in types through their prototypes.. i.e. Number.prototype.foo = function(){} or String.prototype.trim = function(){ ... }
need to extend Number object like this..
var x = Number(5);
Number.prototype.multiplied = function(a) {return this * a;};
Comments
If you want to create fn like multiplied, you need to extend the prototype of a particular type in the following case you need to extend a Native type i.e.
Number.prototype.multiplied = function(n){
return this*n;
}
var x=5; //x is a Number
var y=x.multiplied(6); // return this*6 => this is x => that is 5 => 5*6 = 30;
in general, if you have var1.doSomething(var2); and var1 is an object, you could define 'methods' in this way
function myObject(name){
if(!(this instanceof myObject)){ // in the case you're missing 'new' when you declare a myObject instance
return new myObject(name);
}
this.name = name; //field
this.doSomething = function(param){ //method
alert('done '+param+' '+this.name);
}
}
var var1 = new myObject('peter');
var var2 = "string";
var1.doSomething(var2); //alerts "done string peter"
var var3 = myObject('jean'); //don't need 'new'
var var4 = "homework";
var3.doSomething(var4); //alerts "done homework jean"
var1 could also be a general 'library', and you could define it in this way:
var var1 = {
doSomething : function(param){
alert('done ' + param);
}
}
//you don't need to instantiate a new object. You have a static library
var var2 = "mystring";
var1.doSomething(var2); //alerts "done mystring"
Comments
