How to assign value to global variable in PHP

Question

I have a global variable like

<?PHP
function PrintVariable($str){
   global ${"check" . $str} = "some value";
   echo  $checkmap;    
}
 PrintVariable('map');

but I am getting this error:

Parse error: syntax error, unexpected '=', expecting ',' or ';' in C:\wamp\www\PHP\index.php on line 3

after removing the global from the code everything work fine but I have to create global at this function.

score 3 · Accepted Answer · answered Sep 18 '15 at 00:11

3

There is no combined "declare global and assign value" statement in php.
You'd have to do that in two steps, e.g.

<?php
function foo($str) {
    global ${"check" . $str};
    ${"check" . $str} = "some value";
}

foo('bar');
echo $checkbar;

...but what you really should do is: avoid globals.

answered Sep 18 '15 at 00:11

VolkerK

95,432
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Thanks VolkerK and is it still global? – Mona Coder Sep 18 '15 at 00:14
@MonaCoder Yes it is global. + You could use the `$GLOBALS` array, then you can assign it in one statement – Rizier123 Sep 18 '15 at 00:15
3

As the sample demonstrates: $checkbar can be accessed outside of `function foo()`, so yes, the function sucessfully polluted the global namespace.... – VolkerK Sep 18 '15 at 00:15

score 3 · Answer 2 · edited May 23 '17 at 10:27

3

With the "global" keyword, you can only reference a variable, not set the value of it.

Your code would be:

<?PHP
function PrintVariable($str){
   global ${"check" . $str};
   ${"check" . $str} = "some value";
   echo  $checkmap; // outputs: some value
}
PrintVariable('map');
echo  $checkmap; // outputs: some value

See:

http://php.net/language.variables.scope

Configuration class - Get configuration array from the function string argument

edited May 23 '17 at 10:27

Community

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1

answered Sep 18 '15 at 00:13

ChrisJohns.me

174
2
6

Thanks Christopher_Johns and is it still global? – Mona Coder Sep 18 '15 at 00:15
It is still global. You can call it (outside of the function) as **$checkmap** just as if it were set as a normal variable. – ChrisJohns.me Sep 18 '15 at 00:16

How to assign value to global variable in PHP

2 Answers2