variable declaration

[AMT India]

What is the difference between $a and $$a in php? $a = 10 and $$a = 10 are working as same. But $$$a is not working.

[henryrhenryr]

What is the difference between $a and $$a in php? $a = 10 and $$a = 10 are working as same. But $$$a is not working.

Try the manual: http://www.php.net/manual/en/language.variables.php

Or http://php.net/manual/en/language.variables.variable.php

I think it would work if you used ${${$a}} but not sure.

[pbmods]

Heya, AMT India.

What is the difference between $a and $$a in php?

$$a is a 'variable variable'. PHP evaluates the rightmost part of the expression ($a) and then uses that value with the left part.

So for example:

$name = 'red';
 
$red = 50;
$green = 75;
$blue = 100;
 
echo $$name;  // evaluates to ${'red'} -> $red -> 50
 

$a = 10 and $$a = 10 are working as same. But $$$a is not working.

If you get to the point where you're using variable variable variables, you might want to rethink your application design.