1. Hey Guest Did you know you can win an Honor 10 phone worth ₹33,000 and an additional ₹70,000 in paytm vouchers, just by replying to some threads and taking part in the discussions happening in the Honor Hub?

    What are you waiting for? Start commenting and start winning! Remember to read the instructions posted here.

    Dismiss Notice

Javacsript Help

Discussion in 'Programming' started by Dharmpal Singh, Oct 16, 2009.

Thread Status:
Not open for further replies.
  1. Dharmpal Singh

    Dharmpal Singh New Member

    Joined:
    Jul 31, 2006
    Messages:
    13
    Likes Received:
    0
    Trophy Points:
    0
    Code:
    <html>
    <head>
    <script type="text/javascript">
    function blinking_header()
    {
    if (!document.getElementById('blink').style.color)
    	{
    	document.getElementById('blink').style.color="red";
    	}
    if (document.getElementById('blink').style.color=="red")
    	{
    	document.getElementById('blink').style.color="black";
    	}
    else
    	{
    	document.getElementById('blink').style.color="red";
    	}
    timer=setTimeout("blinking_header()",100);
    }
    
    function stoptimer()
    {
    clearTimeout(timer);
    }
    </script>
    </head>
    
    <body onload="blinking_header()" onunload="stoptimer()">
    <h1 id="blink">Blinking header</h1> 
    </body>
    
    </html>
    Can Any Body explain me these code line by line .
     
  2. krishnandu.sarkar

    krishnandu.sarkar Simply a DIGITian

    Joined:
    Nov 13, 2007
    Messages:
    4,693
    Likes Received:
    15
    Trophy Points:
    38
    Location:
    Kolkata
    Well Let me try....!!

    Code:
    <html>
    <head>
    Starting tag of HTML and HEAD part

    Code:
    <script type="text/javascript">
    Defines the script type which is js in this case

    Code:
    function blinking_header()
    a user defined function named blinking_header is starting


    Code:
    if (!document.getElementById('blink').style.color)
    document means the HTML page(currect page/doc). getElementById is a inbuilt func which gets element id where we passed blink which is a element(we'll see it later) to get its id.
    .style is refers to the style of blink
    .color is a property of style.
    and a !(not) is added to the beginning.

    This means if thr is no color in blink then.....

    Code:
    document.getElementById('blink').style.color="red";
    Again we r fetching the id of element blink which is within document and setting its colour to red.

    Code:
    if (document.getElementById('blink').style.color=="red")
    Now we r checking whether the colour of blink is red


    Code:
    document.getElementById('blink').style.color="black";
    If the avobe condition is true thn we r setting thr colour of blink to Black

    Code:
    else
    	{
    	document.getElementById('blink').style.color="red";
    	}
    Else means if the colour of blink is not red then we r setting the colour to red.
    It is the else part of 2nd if.


    Code:
    timer=setTimeout("blinking_header()",100);
    Now we r setting a clock which will execute this blinking_header() func every 100secs(i forgot is it millisec/sec) and the timer variable will keep track of it.

    And with this the function blinking_header() ends.

    Code:
    function stoptimer()
    {
    clearTimeout(timer);
    }
    Now a new function starts named stoptimer()
    and its stopping the timer i.e the clock.
    clearTimeout is an inbuilt function where we passed timer variable which was keeping track of the clock.


    Code:
    </script>
    </head>
    
    The script and head part ends. The scripts needs to be always declared in head part.

    Code:
    <body onload="blinking_header()" onunload="stoptimer()">
    <h1 id="blink">Blinking header</h1> 
    </body>
    
    </html>
    The body of HTML is starting and onload event(i.e when the page loads i.e startup/releaded) it's calling blinking_header() function and onunload event(i.e when the page unloads(when the page is being unload i.e closed) it's calling the stoptimer() functn.

    Means when the page will load the blinking_header() function starts and keeps changing the colour of blink element from red to black and vice-versa after a desired time(i.e 100 in this case) and continues it.

    And when the page is closed this action stops as the timer is stopped within the fiunction.

    And now we can see that what we are calling element blink is a header of H1.

    Tats all.....!!

    I know my eng is painfull plz manage....!!

    Others plz correct me if I'm wrong.
     
Thread Status:
Not open for further replies.

Share This Page