Functions In JavaScript

Functions In JavaScript

Functions In JavaScript. Now a functions is basically a mini program. Its a mini program that you can use anytime you want through out about your java-Scripting. For example you are making YouTube they probably have a function to play the video whenever you hit the play button. They have a function a pause the video whenever you pause the button. They have a function a function to add a vote to thumbs-up whenever you thumbs-up button as you can see a function can be called not only as soon as a webpage is load but it can be called anytime you want Now Let see example for Making functions in JavaScript's Programming Language.

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Unsetting PHP Session in php

Unsetting php session

Unsetting php session you must read my setting php session to get better understand it. Now in Setting php session we had set the username in set.php and in view we had store username into the session. Now we will create another file unset.php which you can say logout the user. Unset is keyword to remove the stored session variable.

Code for Unsetting php session

set.php (Screenshot1)

Setting PHP sessions (Screenshot1)

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<?php  session_start();   $_SESSION['username']='alex';  ?>

View.php (Screenshot2)

Setting PHP sessions (Screenshot2)

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<?php  session_start();   if (isset($_SESSION['username'])) {  echo 'Welcome. '.$_SESSION['username']';   }else {  echo 'Please log in.';  }   ?>

Unset.php (Screenshot3)

unSetting PHP sessions (Screenshot3)

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<?php   session_start();   unset($_SESSION['username']);  ?>

Output (Screenshot4 , Screenshot5 , Screenshot6):-

Setting PHP sessions (Screenshot4)

Setting PHP sessions (Screenshot5)

Setting PHP sessions (Screenshot6)

Now As you can See in Screenshot4 , Screenshot5 We had unset the variables which is stored in session alex and in Screenshot 6 its again asking for please login now You. Try Your self by again setting php Session and Unsetting php Session.

For Example If You will not rewite session_start() in unset.php. It will not remove variable from the session and session will not be unset.

Let See All output for all set.php , view.php and unset.php

screenshot7

Setting PHP sessions (Screenshot7)

Opening set.php file for setting username as a session variable

Screenshot8

Setting PHP sessions (Screenshot8)

$_SESSION['username']=’alex’; is set to the session variable.

Screenshot9

Setting PHP sessions (Screenshot9)

viewing view.php

Screenshot10

Setting PHP sessions (Screenshot10)

Shows welcome Alex as we can see the Session variable called alex.
Screenshot11

Setting PHP sessions (Screenshot11)

Unset.php file opening

Screenshot12

Setting PHP sessions (Screenshot12)

Will unset the variable which had been set by set.php

Screenshot13

Setting PHP sessions (Screenshot13)

Now You can see view.php is in condition of else because the session variable is unset by unset.php.

Now What if i have more then one session to unset. If i want to unset all session that exit . For That you can try your self

Code for unsetting php session

unset.php

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<?php  session_start();  session_destroy();  ?>

Output (Screenshot14 , Screenshot15 , Screenshot16 , Screenshot17)

Setting PHP sessions (Screenshot14)

Setting PHP sessions (Screenshot15)

Setting PHP sessions (Screenshot16)

Setting PHP sessions (Screenshot17)

Now this session_destroy will unset all session of the website. It will remove all variables of the session which are stored in session.

In Screenshot 17 you can see all session variable had been removed

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