How to for-loop over two arrays in PHP?

Question

Possible Duplicate:
foreach with three variables add

I'm new to PHP so bear with me.

I have a url with two variables like so:

 ?foo=1,2,3,4&bar=a,b,c,d

Both parameters will always have the same amount of elements. I need to loop through the amount of elements like so:

1a
2b
3c
4d

and on each iteration assign two variables for foo and bar value.

If this was javascript no problem, but I have no idea how to do this PHP. This is what I have:

$foo = strtok($rvar_foo,",");
$bar = strtok($rvar_bar,",");
while ( $foo ){
  # now how do I get the corresponding value for $bar?
}

possible duplicate of [Multiple index variables in PHP foreach loop](http://stackoverflow.com/questions/4157810/multiple-index-variables-in-php-foreach-loop) ; [foreach with three variables add](http://stackoverflow.com/questions/7748115/foreach-with-three-variables-add) — hakre, Oct 08 '12 at 21:03
there should also be tons of duplicates for the second part about how to use strtok or convert string to array by comma. — hakre, Oct 08 '12 at 21:05

score 4 · Accepted Answer · edited Oct 08 '12 at 21:04

4

$foo = isset($_GET['foo']) ?  explode(",", $_GET['foo']) :  array();
$bar = isset($_GET['bar']) ?  explode(",", $_GET['bar']) :  array();

for ($i = 0; $i < count($foo); $i++) {
    echo $foo[$i] . $bar[$i] . "<br />";
}

Is this what you want?

Output

1a
2b
3c
4d

edited Oct 08 '12 at 21:04

Baba

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answered Oct 08 '12 at 21:01

h2ooooooo

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not sure. Trying. `Explode` sounds suspicious though ... :-) – frequent Oct 08 '12 at 21:04
@frequent `explode('delimiter', $string)` is like javascripts `string.split('delimiter')` function. – h2ooooooo Oct 08 '12 at 21:05
@frequent very funny ..... :) – Baba Oct 08 '12 at 21:14

score 3 · Answer 2 · edited Oct 08 '12 at 21:30

3

Use array_map:

function my_function($a, $b)
{

    var_dump($a . $b );
    // Do something with both values.
    // The first parameter comes from the first array, etc.
}

array_map("my_function", explode(",",$_GET['a']), explode(",",$_GET['b']));

edited Oct 08 '12 at 21:30

Baba

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answered Oct 08 '12 at 21:18

Platinum Azure

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don't you think `$_GET['a']` needs to an array so it should be `array_map("my_function", explode(",",$_GET['a']), explode(",",$_GET['b']));` – Baba Oct 08 '12 at 21:27
Aw shoot, you're right. I forgot PHP doesn't automatically create arrays there. This is one of many reasons I don't use PHP :-) – Platinum Azure Oct 08 '12 at 21:29
+1 Nice one .. updated your code – Baba Oct 08 '12 at 21:31
Thanks Baba. I thought I remembered a way that PHP would interpret `$_GET` as an array, but I need to look into it. – Platinum Azure Oct 08 '12 at 21:34
everyone forgets once in a while can see you are `phyton` `c++` person – Baba Oct 08 '12 at 21:35

clentfort · Answer 3 · 2012-10-08T21:12:18.740

Maybe you are looking for array_combine. It creates an array from two arrays, using one array for the keys, the other array for the values.

$foo = explode(',', $_GET['foo']);
$bar = explode(',', $_GET['bar']);
$foobar = array_combine($foo, $bar);

This would result in $foobar using the values from $foo as its keys and $bar for the values.

Calling print $foobar[1] would result in a being printed to the output. (You can find a running example here)

How to for-loop over two arrays in PHP?

3 Answers3