- Details
- Written by: Stanko Milosev
- Category: JavaScript
- Hits: 4529
Consider following example:
var Foo=function () {
var number = 1;
self.number = 1;
}
Foo.prototype.bar = function () {
console.log("test");
};
var foo = new Foo();
foo.bar();
Notice here that in line Foo.prototype.bar = function () I didn't write "var".
This code will work perfectly, in console you will see "test".
Now check following code:
var Foo=function () {
var number = 1;
self.number = 1;
return {inc: function() {
self.number = self.number + 1;
}}
}
Foo.prototype.bar = function () {
console.log("test");
};
var foo = new Foo();
foo.bar();
This code will not work, we will receive error "Uncaught TypeError: undefined is not a function", because with return we will loose "this". Solution is to add return this:
var Foo=function () {
var number = 1;
self.number = 1;
return this;
}
Foo.prototype.bar = function () {
console.log("test");
};
var foo = new Foo();
foo.bar();
- Details
- Written by: Stanko Milosev
- Category: JavaScript
- Hits: 4393
Just one simple example about private and public methods in JavaScript.
Check this code in JS:
(function (ns) {
function myCreator () {
var self=this;
function privateMethod() {
alert("Hi I am private method and I can be executed only within myCreator class (I will be never called)");
}
self.publicMethod = function () {
document.getElementById("publicMethodCall").innerHTML = "Hi, I am called from publicMethod";
}
}
ns.myCreator = myCreator;
}(window.privateAndPublic))
Here you can see how private method is declared:
function privateMethod
and public method:
self.publicMethod
When you open console and check what newly created object has, you will see that there is no privateMethod (because it is inaccessible):
Example download from here.
- Details
- Written by: Stanko Milosev
- Category: JavaScript
- Hits: 4378
Here and here I already explained some ways of introducing methods in javascript, and now i will show one more way.
Let's say we have JS like:
(function (ns) {
function myCreator () {
var self=this;
function privateMethod() {
alert("Hi I am private method and I can be executed only within myCreator class (I will never be called)");
}
self.publicMethod = function () {
document.getElementById("publicMethodCall").innerHTML = "Hi, I am called from publicMethod";
}
}
ns.myCreator = myCreator;
}(window.privateAndPublic))
Then, we introduce JS like:
(function (ns) {
function myCreatorReturn() {
var self = this;
self.myCreator = new window.privateAndPublic.myCreator();
return {
myCreator: self.myCreator
}
}
ns.myCreatorReturn = myCreatorReturn;
}(window.myReturn))
Here notice line:
self.myCreator = new window.privateAndPublic.myCreator();
Now we can call method "publicMethod" like:
window.onload = function() {
mCR = new window.myReturn.myCreatorReturn();
mCR.myCreator.publicMethod();
}
Notice line:
mCR.myCreator.publicMethod();
Example download from here.
- Details
- Written by: Stanko Milosev
- Category: JavaScript
- Hits: 4649
One my extended example of listing 5.1.11 from the book Secrets of the JavaScript Ninja.
HTML I will use just to call JS:
<!DOCTYPE html> <html> <head> <script type="text/javascript" src="/index.js"></script> </head> <body> </body> </html>
JS
Function.prototype.curry = function() {
var fn = this,
args = Array.prototype.slice.call(arguments);
return function () {
return fn.apply(this, args.concat(Array.prototype.slice.call(arguments)));
};
}
function Test(a, b, c) {
console.log("Ok I am here and arguments are: " + a + ", " + b + ", " + c + ", ")
}
testCurry = Test.curry(1, 2, 3);
testCurry();
If you look in to console, you will see the result:
Ok I am here and arguments are: 1, 2, 3,