PHP array how to check if all array values exist in other array

Question

I have arrays like these :

$array1 = [1,2,3]; 

$array2 = [3,2,1]; 
$array3 = [2,1,3]; 
$array4 = [2,1,3]; 
$array5 = [1,1,1]; 
$array6 = [3,3,2]; 
$array7 = [1,2,1];
$array8 = [8,9,2];

I want to check how array2 until array8 compare to array1. It should give me expected return like this :

$array2 = [3,2,1]; return 'match'
$array3 = [2,1,3]; return 'match'
$array4 = [2,3,1]; return 'match'
$array5 = [1,1,1]; return 'not match'
$array6 = [3,3,2]; return 'not match'
$array7 = [1,2,1]; return 'not match'
$array8 = [8,9,2]; return 'not match'

I tried to compare it using array_diff() but sometimes the result is not like what I expected, especially if on array2 have two same values.

note : array2 until array8 need to always have all 3 values from array1

Post the code you have tried using the array_diff.

Ropali Munshi
– Ropali Munshi

2019-04-01 12:25:50 +00:00
Commented Apr 1, 2019 at 12:25 — Ropali Munshi
– Ropali Munshi, Commented Apr 1, 2019 at 12:25

Nick · Accepted Answer · 2019-04-01 12:40:25Z

5

You just need to sort both arrays before comparing them e.g.

sort($array1);
for ($i = 2; $i <= 8; $i++) {
    sort(${"array$i"});
    echo "array $i: " . ($array1 == ${"array$i"} ? 'match' : 'no match') . "\n";
}

Output:

array 2: match 
array 3: match 
array 4: match 
array 5: no match 
array 6: no match 
array 7: no match 
array 8: no match

Demo on 3v4l.org

edited Apr 1, 2019 at 12:40

answered Apr 1, 2019 at 12:32

Nick

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3 Comments

vesuviuzzz Over a year ago

thanks for the quick respond sir but if like this $array1 = [7,6,7]; $array2 = [4,7,6]; sort($array1); sort($array2); echo "array " . (empty(array_diff($array1, $array2)) ? 'match' : 'no match') . "\n"; if like that it will return 'array match' when it shouldn't

vesuviuzzz Over a year ago

wow this actually working, may i know the why the first one not working and now this working ? is the magic is on the sorting ?

Nick Over a year ago

The problem with the first code is that array_diff only looks to see if all the values in $array1 are in $array2. In your test case the values in $array1 were 6 and 7, both of which are in $array2 so array_diff returned an empty array which looked like a match. My new code uses an exact comparison, so the arrays have to have the same number of values and each has to be equal to the corresponding value in the other array. See php.net/manual/en/language.operators.array.php

Aniket Sahrawat · Accepted Answer · 2019-04-01 12:27:07Z

4

You can use array_unique() and then array_diff() for this task:

$array1 = array_unique($array1);
$array2 = array_unique($array2);
$result = array_diff($array1, $array2);

Description of array_unique():

array_unique ( array $array [, int $sort_flags = SORT_STRING ] ) : array

array_unique — Removes duplicate values from an array

Sorting type flags:

SORT_REGULAR - compare items normally (don't change types)
SORT_NUMERIC - compare items numerically
SORT_STRING - compare items as strings
SORT_LOCALE_STRING - compare items as strings, based on the current locale.

answered Apr 1, 2019 at 12:27

Aniket Sahrawat

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Comments

Pupil · Accepted Answer · 2019-04-01 12:33:08Z

You need to sort the arrays so that indexing will be comparable.

Take a parent array and add all array elements in it.

Loop over the parent array.

sort() children arrays.

Compare there and you will get results.

Code:

<?php
$array1 = [1,2,3]; 
$array2 = [3,2,1]; 
$array3 = [2,1,3]; 
$array4 = [2,1,3]; 
$array5 = [1,1,1]; 
$array6 = [3,3,2]; 
$array7 = [1,2,1];
$array8 = [8,9,2];


$arr['array_1'] = [1,2,3];
$arr['array_2'] = [3,2,1]; 
$arr['array_3'] = [2,1,3]; 
$arr['array_4'] = [2,1,3]; 
$arr['array_5'] = [1,1,1];
$arr['array_6'] = [3,3,2]; 
$arr['array_7'] = [1,2,1];
$arr['array_8'] = [8,9,2];

$find = [1,2,3];
if (! empty($arr)) {
 foreach ($arr as $key => $elem) {
  sort($arr[$key]);
  if ($arr[$key] == $find) {
   echo "<br/>[" . implode(',', $elem) . "]: Match";
  }
  else {
   echo "<br/>[" . implode(',', $elem) . "]: No Match";
  }
 }
}

Output:

[1,2,3]: Match
[3,2,1]: Match
[2,1,3]: Match
[2,1,3]: Match
[1,1,1]: No Match
[3,3,2]: No Match
[1,2,1]: No Match
[8,9,2]: No Match

Community · Accepted Answer · 2020-06-20 09:12:55Z

1

Although using array_diff is okay, there's an easier way to compare two arrays you can just use ==

<?php

$array1 = [1,2,3]; 

$array2 = [3,2,1]; 
$array3 = [2,1,3]; 
$array4 = [2,1,3]; 
$array5 = [1,1,1]; 
$array6 = [3,3,2]; 
$array7 = [1,2,1];
$array8 = [8,9,2]; 


for($i = 2; $i <= 8; ++$i) {
    sort(${"array$i"});
    echo ${"array$i"} == $array1 ? 'match' : 'not match';
    echo PHP_EOL;
}

output:

match
match
match
not match
not match
not match
not match

PHP MANUAL

$a == $b Equality TRUE if $a and $b have the same key/value pairs.

$a === $b Identity TRUE if $a and $b have the same key/value pairs in the same order and of the same types.

edited Jun 20, 2020 at 9:12

CommunityBot

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answered Apr 1, 2019 at 12:44

Robert

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Comments

Karol Samborski · Accepted Answer · 2019-04-01 12:35:16Z

0

The fastest way would be to convert your array to associative one. You can use array_flip function to achieve it. Then you need only to check difference in keys which should be fast using array_diff_key. For example:

$array1 = [1,2,3]; 
$array2 = [3,2,1]; 
$array3 = [2,1,3]; 
$array4 = [2,1,3]; 
$array5 = [1,1,1]; 
$array6 = [3,3,2]; 
$array7 = [1,2,1];
$array8 = [8,9,2]; 

var_dump(
  empty( // if it's empty then the arrays are identical
    array_diff_key(array_flip($array1), array_flip($array5))
  )
);

But this will only work if you don't care if any array contains duplicate values. If number or order of elements is important then this won't work.

answered Apr 1, 2019 at 12:35

Karol Samborski

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Comments

Riajul Islam · Accepted Answer · 2019-04-01 12:41:50Z

0

at first need to reduce duplicate data from each array by using php array_unique function Then make difference two array by using array_diff function

<?php
    $firstArray = array_unique($firstArray);
    $secondArray = array_unique($secondArray);
    $arrayDiff = array_diff($firstArray, $secondArray);
?>

answered Apr 1, 2019 at 12:41

Riajul Islam

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