array_diff(): Difference between two arrays

This function takes two or more arrays as input and then returns the result array as difference.
$new_array = array_diff ($array1, $array2,....);
Returns all elements of $array1 which are not present in $array2 ($new_array=$array1 without $array2).

Example with two arrays

$first=array('a','b','c','d','e');
$second=array('f','c','b');
$result=array_diff($first,$second);
while (list ($key, $val) = each ($result)) {
echo "$key -> $val <br>";
}
Output is here.
0 -> a 
3 -> d 
4 -> e 
Keys of the first index are retained. ( no re-indexing done here)

Without any common element

$first=array('a','b','c','d','e');
$second=array('f','g','h');
$result=array_diff($first,$second);
while (list ($key, $val) = each ($result)) {
echo "$key -> $val 
"; }
Output is here
0 -> a 
1 -> b 
2 -> c 
3 -> d 
4 -> e 
Keys of the first array is retained without any re-indexing.

associative array with literal keys

$first=array('Fruits1' =>'Banana','Fruits2'=>'Mango','Fruits3'=>'Apple');
$second=array('new_fruit1'=> 'Strawberry','new_fruit2'=>'Mango');
$result=array_diff($first,$second);
while (list ($key, $val) = each ($result)) {
echo "$key -> $val <br>";
}
Output is here
Fruits1 -> Banana 
Fruits3 -> Apple 
For example let us use one array a1 and store text entered by user in a web form after converting the text string to an array. Now to prevent spammers posting URL or posting of some bad words we will develop another array a2 where all negative words we will store. These words we don't want to be present in the first ( a1) array.

Here is the example of how the array_diff works

$a1=array("first", "second", "third","fourth","fifth");
$a2=array("second","fourth","sixth");

$new_array=array_diff($a1,$a2);

while (list ($key, $val) = each ($new_array)) {
echo "$key -> $val <br>";
}
The output of above code is here

0 -> first
2 -> third
4 -> fifth

How array_diff() is used to remove elements from file name array

Visitors Rating
Your Rating




Google+
MAZHAR HUSSAIN

08-08-2010

PLEASE SEND ME SIR!DIFFERENCE BETWEEN FUNCTION AND ARRAY?

Post Comment This is for short comments only. Use the forum for more discussions.




HTML . MySQL. PHP. JavaScript. ASP. Photoshop. Articles. FORUM Contact us
©2000-2018 plus2net.com All rights reserved worldwide Privacy Policy Disclaimer