PHP two array cross-difference set

PHP two array intersection difference set
Array_intersect--Explanation of the intersection of computed arrays
Array Array_intersect (array array1, array array2 [, array ...])


Array_intersect () returns an array that contains all the values in Array1 that also appear in all other parameter arrays. Note The key name remains unchanged.

Example 1. Array_intersect () example

$array 1 = Array ("A" = "green", "Red", "blue");
$array 2 = Array ("b" = "green", "yellow", "red");
$result = Array_intersect ($array 1, $array 2);
?>

This makes $result become:

Array
(
[A] = Green
[0] = Red
)

Array_diff--A description of the difference set of the computed array
Array Array_diff (array array1, array array2 [, array ...])


Array_diff () returns an array that contains all the values in array1 but not in any other parameter array. Note The key name remains unchanged.

Example 1. Array_diff () example

$array 1 = Array ("A" = "green", "Red", "Blue", "Red");
$array 2 = Array ("b" = "green", "yellow", "red");
$result = Array_diff ($array 1, $array 2);
?>


This makes the $result an array (1 = "blue");. Values that occur more than once in $array 1 are treated the same.

Note: Two units are considered identical only if (string) $elem 1 = = = (string) $elem 2 o'clock. That is, when the expression of a string is the same.
Note: Notice that this function checks only one dimension in a multidimensional array. Of course you can use Array_diff ($array 1[0], $array 2[0]); Check for deeper dimensions.

ARRAY_DIFF_ASSOC--the difference set of the computed array with index check

Description
Array Array_diff_assoc (array array1, array array2 [, array ...])


ARRAY_DIFF_ASSOC () returns an array that contains all the values in array1 but not in any other parameter array. Note that unlike Array_diff (), the key name is also used for comparison.

Example 1. ARRAY_DIFF_ASSOC () example

$array 1 = Array ("A" = "green", "b" = "Brown", "c" = "blue", "Red");
$array 2 = Array ("A" = "green", "yellow", "red");
$result = Array_diff_assoc ($array 1, $array 2);

/* The result is:
Array
(
[B] = Brown
[C] = Blue
[0] = Red
)
*/
?>


In the above example, you can see that the key value pair "a" = "green" is in two arrays, so it is not in the output of this function. In contrast, the key-value pair 0 = "Red" appears in the output because the key name of "Red" in the second parameter is 1.

The key value pair key = Two values in value are only in (string) $elem 1 = = = (string) $elem 2 o'clock are considered equal. This means that strict checks are used, and the expression of the strings must be the same.

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