Hi everyone, I’m Chamini prahskthi from SriLanka.
And….
This is the beginning of my JavaScript tutorial. Hope you will
interest to learn JavaScript from beginning. I hope to give you step by step
guide to be expert about JavaScript.
OK,
Do you know???
JavaScript is a client side developing language. JavaScript can be
used to control the web browser. So, Normally JavaScript is use for validations.
like,
Check if you have enter and
valid email address.
Also JavaScript is use to perform events like button clicks.
So let’s move to the lessons. For this developing purpose you just
need a text editor like Notepad++, sublime text etc.
Here I’ll use Notepad++ for demonstration purposes.
First of all I must tell you this. You must have very simple html
knowledge for learn JS (from here I use short form JS for JavaScript).
Ok let’s move on…
JS is used with in HTML tags. Normally it used within <head> tags. But it is okay to use
anywhere in HTML source code. But the standard way is this. When you began to
write a JS code within HTML code, what you have to do first is put <script> tags.
It is like this
Figure 1
Do you know why I have put ,
<script language =”javascript”
type=”text/javascript”?
Here the word 'language' defines what scripting language we are using and type
means the media type we are using.
So, for the first commencement I wish you show this kind of a code
set.
Example one
Figure 2
OK I save this code as string.html. Then run the program and
following image show what I show after run this.
Figure
3
So, let’s clarify what is in the figure 3. You already know that
js is begin with <script> tags.
After beginning of this tags I have write a function document.write .It is a predefine function in
js to write strings in our web page. And other special this is comment that I
have put within js code. You can use /*
…*/ for
multiple line comment and // for single
line comments in js. (Just like Java)
Ok let’s move on another example.
Example two
Figure
4
Result of this source code:
Figure
5
So, I have done something different here. I crated js function
within the js code and called it in the html code.
The function show an alert. Here when you want to create a js
function you need to write basically
Function
function_name(){
Function body
}
That’s all…
It is easy. Isn’t it?
So here I used alert() function.
When an alert function runs, it shows an alert in the web browser. In addition
to that I used button in the web page and I called that js function after click
the button. (it is like an event performing as I mentioned before.
So I think it is enough for today and I will meet you with my next
js tutorial with another new lesson.
Thankyou…
Comments
Post a Comment