How to use array_diff_ukey() function in PHP?

This article will introduce to you how to use the "array_diff_ukey()" function in PHP. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.

array_diff_ukey() function is a built-in function in PHP. It is used to compare two or more arrays of keys using a user-defined function and returns an array that is array1 and does not exist any other array2, array3 or more...

The syntax is as follows:

array_diff_ukey($array1, $array2, $array3..., arr_diffukeyFunction)

Using parameters: This function accepts a minimum of three parameters, while all three parameters are required and one is optional. The parameters are described as follows:

• #$ array1 (mandatory): This array will be compared to other arrays (for example, this array is compared from array1).

• $ array2 (mandatory): Array compared to the first array.

• $ array3 (optional): Array compared to the first array.

arr_diffukeyFunction (mandatory): This is a required user-defined function. Defines a string on which comparison functions can be called. If the first argument is greater than the second argument, the comparison function returns an integer greater than 0.

Return value: Returns an array containing entries in array1 that do not exist in other arrays, for example: -(arra2, arra3, arar4….more). If all values ​​exist in other arrays, the function returns NULL. The return value type is an array.

Example 1:

Input: 
$arr1 = array("one"=>"C Program", "two"=>"PHP Program", "three"=>"Java Program ");
$arr2 = array("one"=>"Java Program", "two"=>"C++ Program", "six"=>"Java Program");

Output: 
Array
(
    [three] => Java Program 
)

Explanation: First two values of arr1 are matched with arr2 and last value 
             not matched so the function returns last value.

Example 2:

Input: 
$arr1=array("one"=>"C Program", "two"=>"PHP Program", "three"=>"Java Program ");
$arr2=array("one"=>"Java Program", "two"=>"C++ Program", "three"=>"Java Program");

Output: 
Array
(
)

Explanation: All values are matched with arr2 so function return null values.

Let us take an example to understand the array_diff_ukey() function.

Program 1: Get two arrays (array1 and array2) and use the user-defined key comparison function (diffukeyFunction).

Simple solution in PHP language:

<?php
  
// Program of array_diff_ukey function in PHP
  
function arr_diffukeyFunction( $one , $two )
{
     if ( $one === $two ) {
         return 0;
     }
     return ( $one > $two ) ? 1 : -1;
}
  
// Driver Code 
  
$arr1 = array (
     "one" => "C Program" , "two" => "PHP Program" , "three" => "Java Program "
);
$arr2 = array (
     "one" => "Java Program" , "two" => "C++ Program" , "six" => "Java Program"
);
  
$result = array_diff_ukey ( $arr1 , $arr2 , "arr_diffukeyFunction" );
print_r( $result );
?>

The output is as follows:

Array
(
    [three] => Java Program 
)

Program 2: Get three arrays (array1, array2 and arra3), and use user-defined Key comparison function (diffukeyFunction).

<?php
  
// Program of array_diff_ukey function in PHP
  
function arr_diffukeyFunction( $one , $two )
{
     if ( $one === $two ) {
         return 0;
     }
     return ( $one > $two ) ? 1 : -1;
}
  
// Driver Code 
  
$arr1 = array (
     "one" => "C Program" , "two" => "PHP Program" , "three" => "Java Program "
);
$arr2 = array (
     "one" => "XML Program" , "two" => "C++ Program" , "four" => "CSS Program"
);
$arr3 = array (
     "five" => "MVC Program" , "six" => "C# Program" , "one" => "ASP .NET Program"
);
  
$result = array_diff_ukey ( $arr1 , $arr2 , $arr3 , "arr_diffukeyFunction" );
print_r( $result );
?>

The output is as follows:

Array
(
    [three] => Java Program 
)

Program 3:

If all values ​​match in other arrays, Null is returned

<?php
  
// Program of array_diff_ukey function in PHP
function arr_diffukeyFunction( $one , $two )
{
     if ( $one === $two ) {
         return 0;
     }
     return ( $one > $two ) ? 1 : -1;
}
  
// Driver Code 
$arr1 = array (
     "one" => "C Program" , "two" => "PHP Program"
);
$arr2 = array (
     "one" => "Java Program" , "two" => "C++ Program"
);
  
$result = array_diff_ukey ( $arr1 , $arr2 , "arr_diffukeyFunction" );
print_r( $result );
?>

The output is as follows:

Array
(
)

Example 4:

If only one array (array1) is used, and a user-defined key comparison function (diffukeyFunction) is used, there is no output and a "RUNTIME ERROR" warning message is given.

<?php
  
//Program of array_diff_ukey function in PHP
  
function arr_diffukeyFunction( $one , $two )
{
     if ( $one === $two ) {
         return 0;
     }
     return ( $one > $two ) ? 1 : -1;
}
  
// Driver Code 
  
$arr1 = array (
     "one" => "C Program" , "two" => "PHP Program" , "three" => "Java Program "
);
  
//take only one array
  
$result = array_diff_ukey ( $arr1 , "arr_diffukeyFunction" );
print_r( $result );
?>

The output is as follows:

No Output

Warning:

PHP Warning:  array_diff_ukey(): at least 3 parameters are required, 2 given in /home/c0177af9f69e897ad93cc9855a9ae415.php on line 23

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