Find intersection/frequency of a word in multiple file - php

Question

<?php
$wordFrequencyArray = array();
function countWordsfrequency($filename) {
global $wordFrequencyArray;
$contentoffile = (file_get_contents($filename));
$wordArray = preg_split('/[^a-zA-Z0-9]/', $contentoffile, -1, NO_EMPTY);
foreach (array_count_values($wordArray) as $word => $count) {
if (!isset($wordFrequencyArray[$word])) $wordFrequencyArray[$word] = 0;
$wordFrequencyArray[$word] += $count;
}
}
$filenames = array('file1.txt', 'file2.txt','file3.txt','file4.txt');
foreach ($filenames as $filename) {
countWordsfrequency($filename);
}
print_r($wordFrequencyArray);
?>
This is the my code to find the frequency of each word in multiple files and print them.Now what i want to do is check find intersection that which word occurs in which files .For example if there is a word "stack" i want to print in which files it occurs and its frequency which i think i have already calculated.
Final result should be like the frequency followed by in which files that word occurs.
How should i proceed with it? Should i check it in the for loop in the countWords function itself.

Answer 1

You will have to save a little more information. I am going to shy away from using classes because it seems like you do not need anything too robust.
<?php
$wordFrequencies = array();
function countWordsFrequency($filename) {
global $wordFrequencies;
$contentoffile = (file_get_contents($filename));
$wordArray = preg_split('/[^a-zA-Z0-9]/', $contentoffile, -1, NO_EMPTY);
foreach (array_count_values($wordArray) as $word => $count) {
$wordFreqInfo = $wordFrequencies[$word];
if (!isset($wordFreqInfo)) {
$wordFreqInfo = array();
$wordFreqInfo['total'] = 0;
$wordFreqInfo['files'] = array();
$wordFrequencies[$word] = $wordFreqInfo;
}
// If this is the first occurence of this word in the file, start a count.
if (!isset($wordFreqInfo['files'][$filename]))
$wordFreqInfo['files'][$filename] = 0;
}
// Increment counts for both the total and the file.
$wordFreqInfo['total'] += $count;
$wordFreqInfo['files'][$filename] += $count;
}
}
$filenames = array('file1.txt', 'file2.txt','file3.txt','file4.txt');
foreach ($filenames as $filename) {
countWordsFrequency($filename);
}
print_r($wordFrequencies);
?>