[php] Are there pointers in php?

No, As others said, "There is no Pointer in PHP." and I add, there is nothing RAM_related in PHP.

And also all answers are clear. But there were points being left out that I could not resist!

There are number of things that acts similar to pointers

  • eval construct (my favorite and also dangerous)
  • $GLOBALS variable
  • Extra '$' sign Before Variables (Like prathk mentioned)
  • References

First one

At first I have to say that PHP is really powerful language, knowing there is a construct named "eval", so you can create your PHP code while running it! (really cool!)

although there is the danger of PHP_Injection which is far more destructive that SQL_Injection. Beware!

example:

Code:

$a='echo "Hello World.";';
eval ($a);

Output

Hello World.

So instead of using a pointer to act like another Variable, You Can Make A Variable From Scratch!


Second one

$GLOBAL variable is pretty useful, You can access all variables by using its keys.

example:

Code:

$three="Hello";$variable=" Amazing ";$names="World";
$arr = Array("three","variable","names");
foreach($arr as $VariableName)
    echo $GLOBALS[$VariableName];

Output

Hello Amazing World

Note: Other superglobals can do the same trick in smaller scales.


Third one

You can add as much as '$'s you want before a variable, If you know what you're doing.

example:

Code:

$a="b";
$b="c";
$c="d";
$d="e";
$e="f";

echo $a."-";
echo $$a."-";   //Same as $b
echo $$$a."-";  //Same as $$b or $c
echo $$$$a."-"; //Same as $$$b or $$c or $d
echo $$$$$a;    //Same as $$$$b or $$$c or $$d or $e

Output

b-c-d-e-f


Last one

Reference are so close to pointers, but you may want to check this link for more clarification.

example 1:

Code:

$a="Hello";
$b=&$a;
$b="yello";
echo $a;

Output

yello

example 2:

Code:

function junk(&$tion)
{$GLOBALS['a'] = &$tion;}
$a="-Hello World<br>";
$b="-To You As Well";
echo $a;
junk($b);
echo $a;

Output

-Hello World

-To You As Well

Hope It Helps.