PHP & check if subarray exists in multidimensional array

Discussion in 'PHP' started by xms, Mar 25, 2017.

0
  1. #1
    I am using PHP.

    I would like to use foreach function and check if two subarrays do exist.

    How can I check whether or not subarrays [1] and [2] do exist?

    As you see here, [1] does exist but [2] does not.

        Array (
      [65] => Array (
        [1] => Array (
        )
      )
    )
    PHP:
     
    Last edited: Mar 25, 2017
    xms, Mar 25, 2017 IP
  2. PoPSiCLe

    PoPSiCLe Illustrious Member

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    #2
    Here:
    
<?php

$test = [
     65 => [
       1 => 'something',
       2 => 'something else',
       ],
     ];

if (is_array($test[65])) {
   foreach ($test[65] as $key => $value) {
     echo $key.' exist';
   }
}
    PHP:
     
    PoPSiCLe, Mar 25, 2017 IP
  3. xms

    xms Active Member

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    #3
    Thanks! How should I modify the foreach loop if I want to create [65][1] and/or [65][2] if they do not exist?
     
    xms, Mar 25, 2017 IP
  4. PoPSiCLe

    PoPSiCLe Illustrious Member

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    #4
    You can't, because the foreach-loop will only read the actual, existing elements. You will have to something else if that's what you want. You could use a for-counter with a predetermined counter and check if the key exists. Something like:
    
for ($c = 1; $c <=2; $c++) {
if (array_key_exists($c,$test[65])) {
   echo 'test[65]['.$c.'] exist';
  } else {
   $test[65][$c] = 'content goes here';
  }
}
    Code (markup):
     
    Last edited: Mar 25, 2017
    PoPSiCLe, Mar 25, 2017 IP
  5. sarahk

    sarahk iTamer Staff

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    #5
    I'm trying to read between the lines and see what you're really up to. 

    $test = [
   65 => [
'sizes' => array('s','m','l'),
'colours' => array('red','blue','yellow')
],
];

foreach($test as $k => $arr){
if (!array_key_exists('sizes', $arr){
 $test[$k]['sizes'] = array('OSFA');
}
if (!array_key_exists('colours', $arr){
     $test[$k]['colours'] = array('black');
}
    PHP:
    and if that's on the right track you can also do this
    $test = [
   65 => [
'sizes' => ['s','m','l'],
'colours' => ['red','blue','yellow']
],
];

$defaults = array[
  'sizes' => ['OSFA'],
  'colours' => ['black']
] 

foreach($test as $k1 => $arr){
  foreach($defaults as $k2 => $defs) {
if (!array_key_exists($k2, $arr){
 $test[$k][$k2] = $defs;
}
}
    PHP:
     
    sarahk, Mar 25, 2017 IP