Comparing contents of two huge arrays 
November 6th, 2008, 01:00 PM
| | Member | | Join Date: Oct 2008
Posts: 82
| | Comparing contents of two huge arrays
Hi,
I have two very huge arrays, the second array contains some of the elements of array1 and also different elements, both are not of the same size, have to find only the elements that are not common in both the arrays, I used array_diff but its not working can some body help me with this??
Thanks in advance
| 
November 6th, 2008, 01:22 PM
|  | Moderator | | Join Date: Jun 2007 Location: York, England, with wolves. Age: 18
Posts: 4,179
| |
Post the code you have tried. Use code tags.
| 
November 6th, 2008, 01:33 PM
| | Member | | Join Date: Oct 2008
Posts: 82
| | - <?
-
$array1=array("++Hello how are you 20000901",
-
"++Hows work 20010201",
-
"++Am doing great 30089254");
-
$array2=array("-+Hows work 20010201",
-
"-+I like PHP 2657656",
-
"-+Am doing great 30089254");
-
$arry3=array_diff($array1,$array2);
-
print_r($arry3);
-
?>
the output should display just first element of array1 i.e ++Hello how are you 20000901
here am just giving a part of the input the actual input has more elements of similar format.
| 
November 6th, 2008, 02:28 PM
|  | Expert | | Join Date: Mar 2007
Posts: 963
| |
The array elements all differ
[PHP]"++Hello how are you 20000901",
"++Hows work 20010201",
"++Am doing great 30089254");
"-+Hows work 20010201",
"-+I like PHP 2657656",
"-+Am doing great 30089254");[/PHP]
| 
November 7th, 2008, 03:03 AM
| | Member | | Join Date: Oct 2008
Posts: 82
| |
Actually I have remove that -+ and ++ and then compare but how do I remove that??
| 
November 7th, 2008, 09:36 AM
|  | Expert | | Join Date: Mar 2007
Posts: 963
| | Quote: |
but how do I remove -+ and ++
| You will have to use string functions to remove.
str_replace is a simple method [PHP]$remove = array('++','-+');
str_replace($remove,'',$array);[/PHP]However this means looping through every array element before doing the array_diff.
You could use one of the array functions that employ a callback function
or array_walk().
Is it not better to strip the operator symbols off the string before inserting in the array?
| 
November 8th, 2008, 03:51 PM
| | Member | | Join Date: Oct 2008
Posts: 82
| |
It is not possible to remove the -+ and ++ before inserting into the array. But how do I use the array_walk?is it possible the function in array_walk to return a value??
| 
November 8th, 2008, 04:44 PM
| | Member | | Join Date: Oct 2008
Posts: 82
| |
Can I create a singly linked list for comparing the arrays?If yes how to do it??
| 
November 9th, 2008, 12:47 PM
| | Member | | Join Date: Oct 2008
Posts: 82
| |
I used the following code to display only non duplicate elements but am not getting the required results can you plz tell me the problem with this code here?? - $rep=array("-+");
-
foreach($array1 as $array) {
-
$x=str_replace($rep,"",$array);
-
array_push($a,$array);
-
}
-
$repl=array("++");
-
foreach($array2 as $array) {
-
$y=str_replace($repl,"",$array);
-
array_push($b,$array);
-
}
-
$c=array_merge($a,$b);
-
$d=array_unique($c);
Last edited by pbmods; November 9th, 2008 at 01:31 PM.
Reason: Added CODE tags.
|  | | Thread Tools | Search this Thread | | | | | | | What is Bytes?
We are a network of experts and professionals in IT and software development that help one another with answers to tough questions and share insights.
Get the best answers to your questions from over 220,662 network members.
|