Difficulty with 'array_column'

Question

I have built an array as follows:

while($row = mysqli_fetch_array($result))
  {
 $universe[] = $row;
}

The print_r output is as follows:

Array ( [0] => 
   Array ( [0] => 1 [ID] => 1 [1] => Russian Federation - Conventional [Misc1] => Russian Federation - Conventional [2] => RUS.Con1 [Misc2] => RUS.Con1 [3] => [Misc3] => [4] => [Misc4] => [5] => 13.13 [1980] => 13.13 [1981] => 13.13 [1982] => 13.13 [1983] => 13.13 [1984] => 13.13 [1985] => 13.13 [1986] => 13.13) 
        [1] => 
   Array ( [0] => 2 [ID] => 2 [1] => Saudi Arabia - Conventional [Misc1] => Saudi Arabia - Conventional [2] => SAU.Con1 [Misc2] => SAU.Con1 [3] => [Misc3] => [4] => [Misc4] => [5] => 4.47 [1980] => 4.47 [1981] => 4.47 [1982] => 4.47 [1983] => 4.47 [1984] => 4.47 [1985] => 4.47 [1986] => 4.47 ) etc ...

I am now trying to get an array of all values in column [1980].. So I do the following, but get a blank. Any ideas? Also -why am I getting an unecessary array wrapping everything?

print_r($universe);
$hi = array_column($universe, '1980');
print_r($hi);

This function requires PHP >= 5.5. What PHP version do you use? — twain
– twain, Commented Dec 12, 2014 at 19:47
that print_r() dump looks so bad i wish i could unsee it... try using var_export($universe) to get better structure dumps — Konstantin
– Konstantin, Commented Dec 12, 2014 at 19:48
Haha Konstantin -you cracked me up. var_export doesn't make much of a difference, just removed the brackets and put quotes instead... I tried to clear it up above. Train, I am using 5.5.6 so this shouldn't be a problem? — Noobster
– Noobster, Commented Dec 12, 2014 at 20:01
@Noobster in every joke there is always a part of joke... The moment i saw your array i stopped reading. How much effort can you expect from me when you don't make any effort yourself? What does this supposed to mean: ... [3] => [Misc3] => [4] => [Misc4] => [5] => 13.13...? This is not php... of course every one is free to do what they want and not everyone has high standards but such a sloppy code feels disrepectful towards the people you ask for help. — Konstantin
– Konstantin, Commented Dec 12, 2014 at 22:08
I think the clue is in my name. If you're not interested in helping then please don't feel obliged. Ragnar got it pretty quickly, and even with my moderate (granted ugly) skills I can work out what that array is doing. Incidentally, the stuff in brackets is the column name. Take it easy -perhaps go out for a smoke. — Noobster
– Noobster, Commented Dec 12, 2014 at 23:36

Ragnar · Accepted Answer · 2014-12-12 20:53:57Z

1

Try this way:

$values = array();
for ($i=0;$i<count($universe);$i++){
    $values[] = $universe[$i]['1980'];
}

Inside your while loop to avoid multiple iterations:

$values = array();
while($row = mysqli_fetch_array($result)){
    $universe[] = $row;
    $values[] = $row['1980'];    
}

edited Dec 12, 2014 at 20:53

answered Dec 12, 2014 at 20:08

Ragnar

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2 Comments

Noobster Over a year ago

Nice one Ragnar. That worked! But I was hoping to use the array_column to speed things up. Is your method fast or will it slow down my script? Say I need to do this for a bunch of columns ... :-)

Ragnar Over a year ago

I think it's fast but if you want you can do it inside your while loop

Kevin_Kinsey · Accepted Answer · 2014-12-12 19:44:59Z

1

You have an array inside your array.

print_r($universe);
$hi = array_column($universe[0], '1980');
print_r($hi);

answered Dec 12, 2014 at 19:44

Kevin_Kinsey

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2 Comments

Noobster Over a year ago

Hello Kkinsey, I tried that already but with no success :) I think this is pointing out to the right direction though. Why do I have these unecessary arrays? How do I remove them?

Kevin_Kinsey Over a year ago

It's in the array construction. You're creating an array of arrays; it will look that way unless you do something different. This approach does make a prettier array: pastebin.com/HQ1PL22A To do that inside a DB loop, perhaps something like this: pastebin.com/a6gXydXx

Konstantin · Accepted Answer · 2014-12-12 22:21:54Z

-1

Your array structure is completely incomprehesible so i won't even bother going into actual code.

But keep in mind that $array[1980] and $array['1980'] are not the same thing. The same goes for array_column

PS. this is what an array looks like:

$array = array(
    array(
        'a' => 'b',
        'c' => 'd',
        ...
        'y' => 'z'
    ),
    array(
        'a' => '1',
        'c' => '3',
        ...
        'y' => '26'
    ),
    ...
);

edited Dec 12, 2014 at 22:21

answered Dec 12, 2014 at 22:13

Konstantin

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1 Comment

Noobster Over a year ago

This is not an answer to the question asked, but thank you for showing me what an array looks like.

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