How To Output Multidimensional Array , With For Loop ?

[printJimy]

Hello .

( explain me plz)How can i output an Multidimensional array with for loop(or while), not with foreach ?

example this array

$exampleMultidmArr = array (
"nested1" =>array (1,2,3,4,5),
"nested2" =>array (7,20,43,44,25),
);

Thank You.

[krisw44]

You could do it with a 'for' loop or a 'foreach' loop. I think it is more a matter of preference and what you are going to do with the data. I tend to use 'for' loops.

 

for(i=0; i < count($exampleMultidmArr); i++)
{
 for(j=0; j < count($exampleMultidmArr[i]); j++)
 {
   echo $exampleMultidmArr[i][j];
 }
}

 

With this method you can do additional things with the data since you are determining the exact position of each item.

 

Hope this helps.

[Christian F.]

If you have a large array, I would recommend putting the count () outside of the for loop.

You'll save about 33% on it, with ~0.02 ms vs ~0.03 ms with 100k iterations, on my test system. So not a whole lot, but it can be noticeable on huge arrays.

[AyKay47]

Just for shiggles, here is an example using while loops:

 

$mArr = array(
0=>array(1, 2, 3, 4, 5),
1=>array(7, 20, 43, 44, 25)
);

$i = 0;
$c = count($mArr);
while($i < $c)
{
 $j=0;
 $c2 = count($mArr[$i]);
 while($j < $c2)
 {
   echo $mArr[$i][$j] . PHP_EOL;
   $j++;
 }
$i++;
}

 

But, using a foreach loop is best.

[Jessica]

print_r is my favorite PHP function.

[printJimy]

Thank to all of you , i really understood issue now .

Also when we have the key of array as a string , we need to use a string also in a loop , example like this ?

is it the right ?

<?php
$mArr = array(
"a"=>array(1, "string", 3, 4, 5),
"b"=>array(7, 20, 43, 44, 25)
);




for ($i="a"; $i<= "b"; $i++)
{


for ($j=0;$j<count($mArr[$i]); $j++)
{


echo $mArr[$i][$j]." ";

}
echo"<br>";
}
?>

[Muddy_Funster]

neither of those two arrays have a string key in them

[AyKay47]

neither of those two arrays have a string key in them

 

"a" and "b" are both string keys.

 

In a situation where you would need to have string keys and do not want to use a foreach loop (why not?), use a persistent naming convention for the keys so you can reference them properly inside of the loop(s). Something like this:

 

$mArr = array(
"number1"=>array(1, 2, 3, 4, 5),
"number2"=>array(7, 20, 43, 44, 25)
);

$i = 0;
$c = count($mArr);
while($i < $c)
{
 $index = "number" . ($i + 1);
 $j=0;
 $c2 = count($mArr[$index]);
 while($j < $c2)
 {
       echo $mArr[$index][$j] . PHP_EOL;
       $j++;
 }
$i++;
}

[Pikachu2000]

You can use array_keys to get the keys into an enumerated array. Then use a for() loop regardless of the values or order of the original keys. Using foreach() would still be a much better solution though, IMO. Iterating over arrays is exactly what it's there for.

 

$mArr = array(
"a"=>array(1, "string", 3, 4, 5),
"b"=>array(7, 20, 43, 44, 25)
);

$keys = array_keys($mArr);
$c = count($keys);

for( $i = 0; $i < $c; $i++ ) {
print_r( $mArr[$keys[$i]] );
echo '<br>';
}

[Iluvatar+]

Why not foreach?

 

Hello .

( explain me plz)How can i output an Multidimensional array with for loop(or while), not with foreach ?

example this array

$exampleMultidmArr = array (
"nested1" =>array (1,2,3,4,5),
"nested2" =>array (7,20,43,44,25),
);

Thank You.

[printJimy]

I'm just learning how to use" for or while" in these situations .

again , thank you too much.

[printJimy]

also i have a question about how to output the key of array with the for loop .

example this is an array and this array have 2 key 1 and 2 , how to output these keys .

$vegetables=array (1=>"apples", 2=>"pear");

and the output of this array i like to be (if it is possible) :

1 apples
2 pear

without any special function like

key();

or something like this .

Thanks

[Christian F.]

Read up on foreach (), and you'll see.

Also, key () isn't a special function in any way, it's been a part of the core PHP functionality since at least 4.x. Granted, it's not often used as foreach () is often the better alternative.

[printJimy]

Read up on foreach (), and you'll see.

Also, key () isn't a special function in any way, it's been a part of the core PHP functionality since at least 4.x. Granted, it's not often used as foreach () is often the better alternative.

i know with foreach ,

foreach ($vegetables as $k => $v) {
 echo $k;
}

, but i want with "for" .

[Christian F.]

Then you have to use key () as well as next (), or each ().

However, in almost every case when you want the key and the value, you'll want to use foreach (). So if this is only for training: Keep it up. Just don't try to avoid foreach () in production code, just "because".

[Barand]

i know with foreach ,

...

but i want with "for" .

 

And would you knock screws in with a hammer, or do the sensible thing and use a screwdriver?

[printJimy]

And would you knock screws in with a hammer, or do the sensible thing and use a screwdriver?

 

Ok , i said that im just learning how to use other loop in these case , but i do not use" for or while" when i work with array , because i know that foreach is constructed for that.

So i just want to know how to use other loop to manipulate with array.

[Jessica]

That makes no sense.

[Beeeeney]

Ok , i said that im just learning how to use other loop in these case , but i do not use" for or while" when i work with array , because i know that foreach is constructed for that.

So i just want to know how to use other loop to manipulate with array.

 

There isn't really a reason that you shouldn't be using foreach for your purpose. I think you're just being awkward.

[printJimy]

ok ok, I will not use never again "for or while" .

Thank to all of you , topic can be closed .

[Beeeeney]

ok ok, I will not use never again "for or while" .

Thank to all of you , topic can be closed .

 

To say you'll never use them again is a bit much, isn't it? I don't want you to leave this forum thinking that for loops and while loops are bad form.

 

Use them for their intended purposes!

[printJimy]

I do not say to leave forum , Now I understood the issue , and i thought not to use a " for " in these situations , not forever(even i said ).

I am here to learn, not to oppose .

[Beeeeney]

If I understand what you just said, and I think I do, then that's good stuff.

[Pikachu2000]

Since you already know foreach() is there for dealing with arrays, if using a for() or while() loop on an array helps you learn how they work, then by all means do it.