PHP Nested loops where values are the key to the next level of the array

Question

I'm relatively new to PHP and I hope you can help me solve my problem. I am selecting out data from a database into an array for timekeeping. Ultimately, I would like to calculate the total number of hours spent on a project for a given customer.

Here is the code to populate a multi-dimensional array: ...

foreach ($record as $data) {  
  $mArray = array();  
  $name = $data['user'];  
  $customer = $data['customer'];  
  $project = $data['project'];  
  $hours = $data['hours'];  

  $mArray[$name][$customer][$project] += $hours;  
}

...

I would now like to iterate over $mArray to generate an xml file like this:

...

foreach ($mArray as $username) {
  foreach ($mArray[$username] as $customerName) {
    foreach ($mArray[$username][$customerName] as $project ) {
        echo '<'.$username.'><'.$customerName.'><'.$project.'><hours>'.
           $mArray[$username][$customerName][$project].'</hours></'.$project.'>
           </'.$customerName.'></'.$username.'>';
    }
  }
}

This nested foreach doesn't work. Can someone give me a couple of tips on how to traverse this structure? Thank you for reading!

UPDATE: Based on the comments I've received so far (and THANK YOU TO ALL), I have:

foreach ($mArray as $userKey => $username) {
  foreach ($mArray[$userKey] as $customerKey => $customerName) {
    foreach ($mArray[$userKey][$customerKey] as $projectKey => $projectName) {
      echo '<name>'.$userKey.'</name>';
      echo "\n";
      echo '<customerName>'.$customerKey.'</customerName>';
      echo "\n";
      echo '<projectName>'.$projectKey.'</projectName>';
      echo "\n";
      echo '<hours>'.$mArray[$userKey][$customerKey][$projectKey].'</hours>';
      echo "\n";
    }
  }
}

This is now only providing a single iteration (one row of data).

Marc B · Accepted Answer · 2012-09-12 19:38:15Z

5

Foreach syntax is foreach($array as $value). You're trying to use those values as array keys, but they're not values - they're the child arrays. What you want is either:

foreach($mArray as $username) {
   foreach($username as ...)

or

foreach($mArray as $key => $user) {
   foreach($mArray[$key] as ...)

answered Sep 12, 2012 at 19:38

Marc B

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6 Comments

Terry Mah Over a year ago

I'm getting closer. I chose your option 2. But now, I'm only getting the first set of data.

Jonathan Kuhn Over a year ago

probably would be better to use something like

foreach($mArray as $username=>$customer){ foreach($customer as $customerName=>$projects){ foreach($project as $project=>$hours){ ...

then you have access to the keys as $username, $customerName, $project and the $hours

Marc B Over a year ago

make sure you use different names for all your $x => $y variables, or your inner loops will overwrite whatever the outer loops are doing.

Terry Mah Over a year ago

Yes. My syntax is correct now, but I'm only getting one row:

Terry Mah Over a year ago

foreach ($mArray as $userKey => $username) { foreach ($mArray[$userKey] as $customerKey => $customerName) { foreach ($mArray[$userKey][$customerKey] as $projectKey => $projectName) { echo '<name>'.$userKey.'</name>'; echo "\n"; echo '<customerName>'.$customerKey.'</customerName>'; echo "\n"; echo '<projectName>'.$projectKey.'</projectName>'; echo "\n"; echo '<hours>'.$mArray[$userKey][$customerKey][$projectKey].'</hours>'; echo "\n"; } } }

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