How to remove values in one array from another array using PHP

Example: I have array A with values and another array B. I need to remove the values in array A from the values in array B.

1. Use the PHP function array_diff
   • Description
     • array array_diff ( array $array1 , array $array2 [, array $ … ] )
     • Compares array1  against array2  and returns the difference.
   • Parameters
     • array1 = The array to compare from
     • array2 = An array to compare against
2. Code example below:

   <?php
   
       $arrayA = array('one','two');
   
       $arrayB = array('one','two','three','four','five');
   
       
   
       $newArray = array_diff($arrayB,$arrayA);
   
       
   
       echo '<pre>';
   
       print_r($newArray);
   
       echo '</pre>';
   
   ?>

3. The code example above will print the following:

   Array
   
   (
   
       [2] => three
   
       [3] => four
   
       [4] => five
   
   )

4. Explanation:
   • Array A values will be removed from array B
   • The $newArray variable will contain the values of array B with values from array A removed

PHP: Sort set based on another table

 I have visited similar question here but not getting what i want in php. Suppose i have 2 arrays. All checking should be case insensitive. say Field0 is same as field0 or fiEld1 is same as Field1.

array1 is array(
"0"=>"field0",
"1"=>"field1",
"2"=>"field2",
"3"=>"field3",
);

array2 is array(
"0"=>"field3",
"1"=>"field2",
"2"=>"field0",
"3"=>"field1",
"4"=>"field6",
"5"=>"field5",
);

Now I want array2 to be sorted based on array1 like the following:

array2 is array(
"0"=>"field0",
"1"=>"field1",
"2"=>"field2",
"3"=>"field3",
"4"=>"field6",
"5"=>"field5",
);

look here array1 has 4 elements so array2 should be sorted based exactly 4 elements of array1 and rest 2 element (index 4,5 of array2) should as it is in array2 before.

---

Try array_intersect combined with array_diff:

<?php
$array1 = array(
    "0"=>"field0",
    "1"=>"field1",
    "2"=>"field2",
    "3"=>"field3",
);

$array2 = array(
    "0"=>"field3",
    "1"=>"field2",
    "2"=>"field0",
    "3"=>"field1",
    "4"=>"field6",
    "5"=>"field5",
);

$array3 = array_merge(
    array_intersect($array1, $array2),
    array_diff($array2, $array1)
);

var_dump($array3);

Update

For a case insensitive approach, use array_map to guarantee all entries in both arrays are lower-cased:

$array3 = array_map('strtolower', $array1);
$array4 = array_map('strtolower', $array2);

$array5 = array_merge(
    array_intersect($array3, $array4),
    array_diff($array4, $array3)
);

var_dump($array5);

array_diff in PHP

PHP array_diff() function returns an array consisting only of those values present in the first input array and not present in any other arrays.

Syntax:  array_diff(array1,array2,array3...)

Parameters Description:
array1 : Required. The first array will be compared with other arrays.
array2 : Required. An array to be compared with the first array.
array3 : Optional. An array to be compared with the first array.

Tip : The first array can compare with single array or more arrays.
Note : Compare only values of the array.

Example:

<?php
$daysarr1 = array(0=>"Sunday",1=>"Monday",2=>"Tuesday",3=>"Wednesday");
$daysarr2 = array(4=>"Monday",5=>"Tuesday",6=>"Friday");
print_r( array_diff($daysarr1,$daysarr2) );
?>

Output:

Array (
          [0] => Sunday
          [3] => Wednesday
       )