PHP - variable scope inside if statement and while loop

Question

I know that if statement gives a result as a Boolean.

     <?php 
            if (isset($_GET['subj'])) {
            $sel_subj = $_GET['subj'];
            $sel_page = "";
     ?>

Can i use $sel_subj or $sel_page outside if statement ? The second question in the case of while loop ? Can i use a variable outside it or its considered as in the local scope ?

while ($page = mysql_fetch_array($page_set)) {
                echo "<li";
                if ($page["id"] == $sel_page) { echo " class=\"selected\""; }
                echo "><a href=\"content.php?page=" . urlencode($page["id"]) .
                "\">{$page["menu_name"]}</a></li>";
        }

Egg Vans · Accepted Answer · 2013-08-13 10:39:27Z

2

Basically yes, any variables defined inside an if or while will be available in the scope that the if or while exists in (as they are defined in a conditional though they might not have been set so you would receive an undefined warning)

so

    function foo(){
        $i=0
        while($i==0){
           $i=1;
           $a=1;
        }

        echo $a;
        //$a is available here although it might be undefined as the condition may not have been met

    }
    echo $a //$a is not available here

You should ideally declare the variable first.

edited Aug 13, 2013 at 10:39

answered Aug 13, 2013 at 10:02

Egg Vans

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2 Comments

Kareem El-Hennawy Over a year ago

i am sorry i make some changes on what i wrote so.. i think your answer now will be different

Egg Vans Over a year ago

No it's basically the same, unlike say Java where a variable declared within a while loop (or if branch) is only available within that branch in php its available within the scope that the which (or if) has.

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