PHP array_diff () function
Examples
Comparison of two arrays of keys and returns the difference set:
<?php
$a1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$a2=array("e"=>"red","f"=>"green","g"=>"blue");
$result=array_diff($a1,$a2);
print_r($result);
?>
$a1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$a2=array("e"=>"red","f"=>"green","g"=>"blue");
$result=array_diff($a1,$a2);
print_r($result);
?>
Running instance »
Definition and Usage
array_diff () function is used to compare two (or more) of the array keys, and returns the set difference.
This function compares two (or more) key array, and returns a difference of arrays, the array includes all the compared array (array1), but not in any other parameter array (array2 or array3 etc. ) of the key.
grammar
array_diff( array1,array2,array3... );
参数 | 描述 |
---|---|
array1 | 必需。与其他数组进行比较的第一个数组。 |
array2 | 必需。与第一个数组进行比较的数组。 |
array3,... | 可选。与第一个数组进行比较的其他数组。 |
technical details
return value: | Returns a difference of arrays, the array includes all the compared array (array1), but not in any other parameter array (array2 or array3 etc.) in the key. |
---|---|
PHP version: | 4.0.1+ |
More examples
Example 1
Comparison of three arrays of keys, and returns the difference between sets:
<?php
$a1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$a2=array("e"=>"red","f"=>"black","g"=>"purple");
$a3=array("a"=>"red","b"=>"black","h"=>"yellow");
$result=array_diff($a1,$a2,$a3);
print_r($result);
?>
$a1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$a2=array("e"=>"red","f"=>"black","g"=>"purple");
$a3=array("a"=>"red","b"=>"black","h"=>"yellow");
$result=array_diff($a1,$a2,$a3);
print_r($result);
?>
Running instance »
Complete PHP Array Reference