variable variables

Question

how do i create variable variables inside a for loop?

this is the loop:

for ( $counter = 1; $counter <= $aantalZitjesBestellen; $counter ++) {

}

inside this loop i would like to create a variable $seat for each time it passes but it has to incrementlike so. first time it passes it should be $seat1 = $_POST['seat'+$aantalZitjesBestellen], next time it passes: $seat2 = $_POST['seat'+$aantalZitjesBestellen] and so on.

so at the end it should be:

$seat1 = $_POST['seat1'];
$seat2 = $_POST['seat2'];

and so on.

so the variable and the content of the $_POST should be dynamic.

Really you should be changing the values in $_POST variables. Are you doing this because you want to update values on a form you are displaying? If this is the case you might want to consider using javascript for this. — PhoebeB, Aug 24 '10 at 09:25

score 6 · Accepted Answer · answered Aug 24 '10 at 09:23

Firstly, I would use an array for this unless I'm missing something. Having variables like $seat1, $seat2, etc tends to have far less utility and be far more cumbersome than using an array.

That being said, use this syntax:

for ( $counter = 1; $counter <= $aantalZitjesBestellen; $counter ++) {
  $key = 'seat' . $counter;
  $$key = $_POST[$key];
}

Lastly, PHP has an inbuilt function for extracting array keys into the symbol table: extract(). extract() has enormous potential security problems if you use it with unfiltered user input (eg $_POST) so use with caution.

And it's strongly discougared to use extract() as it can open security holes in your application. — Lekensteyn, Aug 24 '10 at 09:25

score 3 · Answer 2 · answered Aug 24 '10 at 09:28

3

This will work as well:

for ( $counter = 1; $counter <= $aantalZitjesBestellen; $counter ++) {
    ${'seat' . $counter} = $_POST['seat' . $counter];
}

answered Aug 24 '10 at 09:28

nubbel

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I prefer this syntax (though I usually use it for properties, not local variables). – strager Aug 24 '10 at 13:11

score 2 · Answer 3 · edited May 23 '17 at 12:07

2

(Expanded for clarity - you may be able to do a one-liner)

for ( $counter = 1; $counter <= $aantalZitjesBestellen; $counter ++) {
    $varname = 'seat' . $counter;
    $$varname = $POST[$varname];
}

BUT! You really shouldn't do this. (And if you really must, see cletus' answer for the built-in PHP way to do it - this is considered bad practice too, though.)

Reconsider your problem and see if arrays might be the solution (I guess it will). This will make both inspection (via e.g. var_dump()) and iteration easier and does not pollute the global variable space.

edited May 23 '17 at 12:07

Community

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answered Aug 24 '10 at 09:22

jensgram

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This is such bad practice... An array would be so much healthier – Pekka Aug 24 '10 at 09:23
1

@Pekka Agree (but this answers OP's question). I will elaborate on my answer :) – jensgram Aug 24 '10 at 09:25

score 0 · Answer 4 · answered Aug 24 '10 at 09:23

0

for ( $counter = 1; $counter <= $aantalZitjesBestellen; $counter ++) {
   $name = 'seat' . $counter;
   $$name = $_POST['seat' . $counter];
}

It's recommended to use arrays, as you can check them easier.

answered Aug 24 '10 at 09:23

Lekensteyn

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score 0 · Answer 5 · answered Aug 24 '10 at 09:30

0

You can use extract but I don't recommended to do what you are trying to do.

answered Aug 24 '10 at 09:30

mathk

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variable variables

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