PHP, "Foreach" using 3 arrays

Question

Possible Duplicate:
foreach with three variables add

If I have 3 arrays of the same size, is it possible to use the costruct foreach() to cycle in the same time the 3 arrays?

ex.

$name contains names

$surname contains surnames

$address contains addresses.

Can foreach take elements [1], [2], [.....] in the same time, to print

$name[1], $surname[1], $address[1];

$name[2], $surname[2], $address[2];

and so on?

Please choose variable names wisely for fairy tale code (or example code as you will), `$1` is not a valid variable name :) — Ja͢ck, Dec 28 '12 at 14:36

score 21 · Answer 1 · answered Dec 28 '12 at 14:34

21

SPL's multipleIterator is designed for precisely this purpose

$mi = new MultipleIterator();
$mi->attachIterator(new ArrayIterator($array1));
$mi->attachIterator(new ArrayIterator($array2));
$mi->attachIterator(new ArrayIterator($array3));

foreach ( $mi as $value ) {
    list($name, $surname, $address) = $value;
    echo $name , ' => ' , $surname , ' => ' , $address , PHP_EOL;
}

answered Dec 28 '12 at 14:34

Mark Baker

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Nice. Would this automatically handle the case that the arrays didn't contain the same number of elements? – Sean Bright Dec 28 '12 at 14:41
I'm interested in the same question. By the way, thanks, this seems what I was searching for. – Mewster Dec 28 '12 at 14:42
Probably not, because of the list construct. If one of the arrays had two indexes I believe it would fail. – David Harris Dec 28 '12 at 14:46
You can change the `MultipleIterator` constructor and pass in `MultipleIterator::MIT_NEED_ANY` which will cause the loop to execute for each element in the longest of the arrays. The default is `MultipleIterator::MIT_NEED_ALL` which is will only run while *every* array has an element in the current slot. – Sean Bright Dec 28 '12 at 14:50
Take a look at the optional flags for the array constructor - http://www.php.net/manual/en/multipleiterator.construct.php = which shows how to match up the arrays by numeric or associative indexes – Mark Baker Dec 28 '12 at 14:53
it perfectly worked for me Mark Baker, thank you so much, it solved my big problem – G'ulomjon Sulaymonov Mar 28 '19 at 06:56
Awesome, it still works in PHP 7 and 8. So much thanks – lewishole Jun 18 '21 at 04:28

score 7 · Answer 2 · answered Dec 28 '12 at 14:34

7

Assuming they are all the same length:

for ($i = 0; $i < count($names); $i++) {
    echo "{$names[$i]}, {$surnames[$i]}, {$addresses[$i]}";
}

answered Dec 28 '12 at 14:34

Sean Bright

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I prefer to use foreach to have more security – Mewster Dec 28 '12 at 14:36
... How does using foreach offer more security?..... – David Harris Dec 28 '12 at 14:37
well, according to php.net, foreach was meant to be used with arrays... – Mewster Dec 28 '12 at 14:38
3

Yikes. OK. Good luck to you. – Sean Bright Dec 28 '12 at 14:38
Yes, but using a for loop and accessing the indexes of the array functions the same, and faster. – David Harris Dec 28 '12 at 14:39
The most easy and logical way to deal with this situation is using *for* I could not see any considerable reason to stick with *foreach* in such case. – SaidbakR Dec 28 '12 at 14:45

LukLed · Answer 3 · 2012-12-28T15:16:22.280

4

You can do it like that (if arrays have the same keys):

foreach ($name as $key => $value) {
    //use $name[$key], $surname[$key], $address[$key]
}

$key contains key in $name array

$value = $name[$key]

edited Dec 28 '12 at 15:16

answered Dec 28 '12 at 14:34

LukLed

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What is $value? I tried to read the php.net documentation but I couldn't understand that part. – Mewster Dec 28 '12 at 14:37
Pleae look at answer again. – LukLed Dec 28 '12 at 14:38
oh thanks, it wasn't there the first time :P – Mewster Dec 28 '12 at 14:38

score 1 · Answer 4 · answered Dec 28 '12 at 14:35

1

Try this

foreach($arr1 as $i => $val) {
    var_dump($val, $arr2[$i], $arr3[$i]);
}

answered Dec 28 '12 at 14:35

Stephen

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score 0 · Answer 5 · answered Dec 28 '12 at 14:35

0

If the array keys are the same you can use key() function.

But you can pass the key to foreach($array as $key => value()){} This way you can refer to the key by the variable without using a function.

answered Dec 28 '12 at 14:35

Sinan

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PHP, "Foreach" using 3 arrays

5 Answers5