Retrieving data from CSV in PHP - php

Question

I have a CSV file containing two rows of data, one which the user will input and the other will be returned. e.g. inputting a post/zipcode which will be found in the CSV file, the data in the next cell should be returned.
<?php
function csv_to_array($filename='bn.csv', $delimiter=',')
{
if(!file_exists($filename) || !is_readable($filename))
return FALSE;
$header = NULL;
$data = array();
if (($handle = fopen($filename, 'r')) !== FALSE)
{
while (($row = fgetcsv($handle, 1000, $delimiter)) !== FALSE)
{
if(!$header)
$header = $row;
else
$data[] = array_combine($header, $row);
}
fclose($handle);
}
return $data;
}
function search($data, $x) {
for($i = 0; $i < sizeof($data); $i++) {
if($data[$i] == $x) return $i;
}
return -1;
}
$data = array("bn.csv");
echo search($data, "BN1 1AA");
print_r(csv_to_array('bn.csv'));
?>
Currently I am just getting -1 returned, what should I do?
Thanks in advance.

Answer 1

$data = array("bn.csv"); creates an array with the literal string bv.csv in it. I'm guessing you want $data = csv_to_array("bn.csv"); here instead. I would build an associative array like this:
$data = [
'BN1 1AA' => 'E05002432',
'...' => '...',
'...' => '...',
];
Via something like:
while (($row = fgetcsv($handle, 1000, $delimiter)) !== FALSE) {
$data[$row[0]] = $row[1];
}
Thus, you can refer to an entry directly by its key, you don't need to iterate over every item to search for a match:
$search = 'BN1 1AA';
if (array_key_exists($search, $data)) {
echo $data[$search];
} else {
echo "not found";
}

Answer 2

There are several problems towards the end of your code.
In search() - you are trying to match the postcode with the entire row in $data[$i] == $x, $data[$i] is actually a list of the fields in the row, so perhaps matching it with ($data[$i][$field] == $x) and $field is the field name of the postcode.
You were calling search() with an array of the file names for the data and not the data from the file, so this code calls csv_to_array() first and passes the result to search()...
Lastly - the sample data didn't have BN1 1AA in it anyway, so should return -1.
function search($data, $x, $field = 'Postcode') {
for($i = 0; $i < sizeof($data); $i++) {
if ($data[$i][$field] == $x)
return $i;
}
return -1;
}
$data = csv_to_array('a.csv');
print_r($data);
echo search($data, "BN1 1AD");