[RESOLVED] How to read the values in two dimensional arrays

rtcary

I put the values of the results of a MySQL select into an array, $data_out. The structure of the array is as follows:

$data_out[$row_num][$field_name]

Normally I do a
for ($i = 0; $i < count($salespersons->data_out); $i++) {
echo $salespersons->data_out[$i]["Firstname"] . "<br>";
}

That works great, however I now would like to get all of the field names (e.g. Firstname, Lastname, etc.) in row zero (0) so I can print the header for a CSV file, then for each field in each row, get the value.

This should be easy, but I'm confused on getting the count of the second index of the array and transversing it.

Todd

sneakyimp

This would depend on how you retrieve the results of the MySQL select.

It looks like $salespersons->data_out is a numerically indexed array. That means you refer to its elements by numbers. E.g.,
$salespersons->data_out[0]
$salespersons->data_out[1]
$salespersons->data_out[2]
etc.

It looks like each element within $salespersons->data_out is an associatively indexed array. I.e., you refer to its elements using a string or associative key like "Firstname".

You can easily inspect the contents of an associative array using [man]var_dump[/man] or [man]print_r[/man] or [man]var_export[/man].

You can inspect the keys of some array using [man]array_keys[/man].

You can manually iterate through the values of an associative array and get its keys at the same time like so:

// outputs all the values associated with person 0
foreach($salespersons->data_out[0] as $key => $value) {
  echo $key . " has a value of " . $value . "\n";
}

NogDog

I might approach it this way:

$fh = fopen('output_file.csv', 'w');
$headersOutput = false;
foreach($data_out as $data) {
    if(!$headersOutput) {
        fputcsv($fh, array_keys($data);
        $headersOutput = true;
    }
    fputcsv($fh, $data);
}
fclose($fh);

rtcary

Thank you both! Both are easy to understand solutions. Does this forum have a way to mark a thread as Solved?

Todd

NogDog

Click "Thread Tools" at the top of the thread, and select "Mark thread resolved" (or something like that).