PHP Variable within For Loop

Question

Hi I have the following:

$q1 = $_POST["q2"];
$q2 = $_POST["q2"];
$q2 = $_POST["q2"];

What I'd like to do is put this within a For loop, as follows:

for ($i=1; $i<=3; $i++){
    $q1 = $_POST["q".$i.""];
}

I can add the variable to the POST part no problems but I cannot work out how to have the 1 next to the $q as a variable:

$q1 = $_POST["q".$i.""];

I'm sure it's simple but I cannot fathom it!

this should work $_POST["q".$i]

user1646111
– user1646111

2013-07-25 10:22:34 +00:00
Commented Jul 25, 2013 at 10:22 — user1646111
– user1646111, Commented Jul 25, 2013 at 10:22

Nikola Kirincic · Accepted Answer · 2013-07-25 10:30:57Z

1

try this

$q_arr = array(); //create empty array
for ($i=1; $i<=3; $i++){
    if(isset($_POST["q".$i])) //first check existance of $_POST item with wanted key 
    $q_arr['q'.$i] =  $_POST["q".$i]; //store it in array

}
extract($q_arr);  //extract creates variables naming them as their key 
if(isset($q1)) //just for test 
echo $q1; //just for test

answered Jul 25, 2013 at 10:30

Nikola Kirincic

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Comments

Vitaly Muminov · Accepted Answer · 2013-07-25 10:24:54Z

1

Check the 'variable variables' feature available in php here. Your code will be similar to this:

$varName  = 'q' . $i;
$$varName = $_POST[$varName]

Also, check out the extract function

answered Jul 25, 2013 at 10:24

Vitaly Muminov

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3 Comments

Richard A. Over a year ago

This would work, but it just feels wrong to do it this way unless you are forced to not use array for some reason. +1 for a valid answer, though not one I agree with.

Vitaly Muminov Over a year ago

i agree with you, variable variables are never safe

Homer_J Over a year ago

Thanks but wanted to avoid using variable variables if poss.

user1646111 · Accepted Answer · 2013-07-25 10:28:42Z

1

for ($i=1; $i<=3; $i++){
    ${"q$i"} = $_POST["q$i"];
}
echo $q1;

Using variable variables can easily assign $q1

answered Jul 25, 2013 at 10:28

user1646111

Comments

Martijn · Accepted Answer · 2013-07-25 10:30:46Z

1

Do you mean this:

// As array:
$q[ $i ] = $_POST['q'.$i]; // this one is my prefered

// Or as object:
$q->$i = $_POST['q'.$i];

edit: removed the eval() version, You simply should not use that. The array one should work just fine :)

You cán use variable variables, but you shouldn't. It get very complicated real fast.

$name1 = 'myName'; 
$example = "name".$i;
echo $$example;

edited Jul 25, 2013 at 10:30

answered Jul 25, 2013 at 10:24

Martijn

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2 Comments

Martijn Over a year ago

That did not work. $a='a'; $b='b'; echo $a.$b; will concat to 'ab' with a dot. I removed the example, it was bad practice anyway :)

Mr. Alien Over a year ago

Yap, I got the explanation :)

Richard A. · Accepted Answer · 2013-07-25 10:25:12Z

0

Would defining your $q variables as an array help?

$q[i] = $_POST["q".$i.""];

answered Jul 25, 2013 at 10:25

Richard A.

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Comments

pythonian29033 · Accepted Answer · 2013-07-25 10:27:03Z

0

do you mean you want to create the variable names dynamically? like this:

for ($i=1; $i<=3; $i++){
   $varname = "q" . $i;
   $$varname = $_POST["q".$i.""];
}
print $q2;

answered Jul 25, 2013 at 10:27

pythonian29033

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