Php Array_Search issue

Question

I've been trying to work with the array_search function.

This is my array :

array (size=23)
  0 => 
    array (size=3)
      0 => string '15' (length=2)
      1 => float 115.08386533184
      2 => string '2014-02-06 21:00:00' (length=19)
  1 => 
    array (size=3)
      0 => string '81' (length=2)
      1 => float 100.41587590619
      2 => string '2014-03-28 00:00:00' (length=19)
  2 => 
    array (size=3)
      0 => string '65' (length=2)
      1 => float 99.096448338334
      2 => string '2014-02-08 21:00:00' (length=19)
  3 => 
    array (size=3)
      0 => string '53' (length=2)
      1 => float 98.752479251378
      2 => string '2014-03-05 12:00:00' (length=19)
  4 => 
    array (size=3)
      0 => string '24' (length=2)
      1 => float 98.303557178126
      2 => string '2014-02-07 21:00:00' (length=19)
  5 => 
    array (size=3)
      0 => string '23' (length=2)
      1 => float 98.270536817788
      2 => string '2014-02-08 21:30:00' (length=19)
  6 => 
    array (size=3)
      0 => string '37' (length=2)
      1 => float 98.139812350661
      2 => string '2014-02-06 23:00:00' (length=19)
  7 => 
    array (size=3)
      0 => string '13' (length=2)
      1 => float 97.810954038756
      2 => string '2014-02-09 19:45:00' (length=19)
  8 => 
    array (size=3)
      0 => string '22' (length=2)
      1 => float 95.975221202728
      2 => string '2014-02-11 20:30:00' (length=19)
  9 => 
    array (size=3)
      0 => string '66' (length=2)
      1 => float 94.115075316114
      2 => string '2014-02-04 19:00:00' (length=19)
  10 => 
    array (size=3)
      0 => string '52' (length=2)
      1 => float 93.957291067159
      2 => string '2014-03-15 00:00:00' (length=19)
  11 => 
    array (size=3)
      0 => string '12' (length=2)
      1 => float 89.188128768086
      2 => string '2014-05-17 10:00:00' (length=19)
  12 => 
    array (size=3)
      0 => string '51' (length=2)
      1 => float 88.381986169995
      2 => string '2014-03-27 12:00:00' (length=19)
  13 => 
    array (size=3)
      0 => string '98' (length=2)
      1 => float 85.240471279545
      2 => string '2014-02-17 18:00:00' (length=19)
  14 => 
    array (size=3)
      0 => string '92' (length=2)
      1 => float 82.721601210972
      2 => string '2014-02-06 20:15:00' (length=19)
  15 => 
    array (size=3)
      0 => string '82' (length=2)
      1 => float 82.473535719129
      2 => string '2014-02-27 17:00:00' (length=19)
  16 => 
    array (size=3)
      0 => string '121' (length=3)
      1 => float 56.833974620724
      2 => string '2014-02-07 22:30:00' (length=19)
  17 => 
    array (size=3)
      0 => string '120' (length=3)
      1 => float 36.269423317467
      2 => string '2014-02-06 21:30:00' (length=19)
  18 => 
    array (size=3)
      0 => string '83' (length=2)
      1 => float 35.863780709688
      2 => string '2014-02-21 07:00:00' (length=19)
  19 => 
    array (size=3)
      0 => string '35' (length=2)
      1 => float 24.322967350005
      2 => string '2014-02-07 21:30:00' (length=19)
  20 => 
    array (size=3)
      0 => string '6' (length=1)
      1 => float 19.71405484708
      2 => string '2014-02-14 22:00:00' (length=19)
  21 => 
    array (size=3)
      0 => string '45' (length=2)
      1 => float 19.142717452481
      2 => string '2014-03-15 00:00:00' (length=19)
  22 => 
    array (size=3)
      0 => string '117' (length=3)
      1 => float 17.641278106673
      2 => string '2014-02-18 17:30:00' (length=19)

Now - The thing is I'm using array_search in order to get the key of a specific ID (Note : The ID is the first value in each array). The thing is, it doesn't work, probably because it can't get the key of the array itself.

Let me show you an example : ($array = The array above)

$r = array_search(53, array_keys($array));

I want $r to be equal to 3, because thats they array's key position. Any idea how I can do it?

Answer 1

$r = array_search('53', array_map(function($x) { return $x[0]; }, $array));

array_map will construct an array of element 0 of each element of the array. Then you search for 53 in this, and $r will be its position.

Or you could simply write a loop:

foreach ($array as $i => $el) {
    if ($el[0] == '53') {
        $r = $i;
        $result = $el;
        break;
    }
}

Answer 2

I searched SO and found a similar topic: PHP Multidimensional Array - Search for value and get the sub-array .

I slightly modified one of the solutions provided above.

$id=53;
$r=null;
$data=null;

foreach ($array as $idx=>$subArray) {
  if ( $subArray[0] == $id ) {
    $r=$idx;
    $target=$subArray;
    break;
  }
}

Answer 3

use array_map function and array_filter function .

function find($a, $id) {
    return ($a[0] == $id) ? $a : false;
}
function filter($a) {
    return $a;
}

$r = array_filter(array_map("find", $array, array(53)), "filter");

Answer 4

A better call than array_map() to isolate the first column of values is: array_column() . This is the task that the function was created for.

Use this implementation:

$r = array_search('53', array_column($array,0));

Done.