How to set javascript private variables in constructor?
You have to put all functions that need to access the private variable inside the constructor:
function Foo(bar)
{
//bar is inside a closure now, only these functions can access it
this.setBar = function() {bar = 5;}
this.getBar = function() {return bar;}
//Other functions
}
var myFoo = new Foo(5);
myFoo.bar; //Undefined, cannot access variable closure
myFoo.getBar(); //Works, returns 5
One of the best tutorials on private and protected access in javascript is here: http://javascript.crockford.com/private.html.
function Foo(a) {
var bar = a; // private instance data
this.getBar = function() {return(bar);} // methods with access to private variable
this.setBar = function(a) {bar = a;}
}
var x = new Foo(3);
var y = x.getBar(); // 3
x.setBar(12);
var z = x.bar; // not allowed (x has no public property named "bar")