concatination of a string with a loop

[Anon]

I am runnning two for loops, one within another. The first one is looking at each word within a string entered on a page, the second for loop then runs through an array and checks each of the words taken from the string and compares it. If it is not found in the string then I want this word to be put into another string - concatinating the string everytime a word taken from the first string does not appear in the array. In the end I want a string which contains all the words which do not appear in my array.

My problem is that the second for loop is concatinating the words from the original string everytime the loop does not find a match.
I understand what the problem is and why it is happening but have no idea how to tackle it!

Here is my code :

for ($i=0; $i < count($splitstr); $i++)
{

for ($x=0; $x < count($excwords); $x++)
{
if ($splitstr[$i] != $excwords[$x]){
$finalstr = $splitstr[$i];
$foundstr .= " " . $finalstr;
}
}

}
echo($foundstr);

Any help would be much appreciated.

[[deleted]]

You have a small problem with the order of events.

The second loop should only decide wether the string is found or not. It should not yet concatenate.

So, instead of concatenating, you should set a var and later check that var.

for ($i=0; $i < count($splitstr); $i++)
{
#assume we are not going to find it.
$found=0;
for ($x=0; $x < count($excwords); $x++)
{
if ($splitstr[$i] == $excwords[$x])
{

The word is found, set the var

$found=1;
};
if ($found==0)
{

the word was not found, contatenate it.

$finalstr = $splitstr[$i];
$foundstr .= " " . $finalstr;
}
}
}

[Anon]

Many thanks for your help Vincent.

I still have bit of a problem though.

Example ...

I have 'is' in my $excwords array and this particular word is the 10th value in my array.
What is happening is that until the 'is' word is found in the string entered by the user it concatenated 'is' 9 times together - or until the it found a match.

If the word is not found in the array, then this word is concatenated together 23 times too (I have 23 words in my array and if the word in the original string is not found it repeats it 23 times because it has not found a match - but I only want it to appear once).

Basically what I am trying to do is pass a string from one page to another stripping out certains words from my array so that only the keywords are left, so I can write an SQL query based on these keywords.

Thanks for your help once again!

[[deleted]]

Are you using php 4?
If so, you can just take your array of keywords, and an array of the words you want to process, and do an array_diff() to get the differences between the two arrays, or an array_intersect() to get the common elements.

[Anon]

I shall give this a try as I am using PHP 4.
Thanks for all your help.