PHP foreach，如何从数组中的键循环

Question

I have an array returned from a DB and I'm trying to echo the output of each field, where the IDS are the same from within, and then moving on to the next ID, until finished. So it prints out all the ID "1s", then "2s", then when its finished it stops. The number of ID's is variable from 1-950.

array ( 0 => stdClass::__set_state(array
( 'Year' => '2017', 
'Month' => 'January',
 'name' => 'Faults', 
'id' => '1', 
'value' => '14058', )),



1 => stdClass::__set_state(array( 
'Year' => '2017',
 'Month' => 'February', 
'name' => 'Faults', 
'id' => '1', 
 'value' => '21', )),




2 => stdClass::__set_state(array
( 'Year' => '2017',
 'Month' => 'January',
 name' => 'Errors', 
'id' => '2', 'value' => '22874', )), 

3 => stdClass::__set_state(array( 
'Year' => '2017', 
'Month' => 'February', 
'name' => 'Errors',
'id' => '2',  
'value' => '2650', )), )

I am trying to achieve an output like this:

January 2017 Faults = 14958
February 2017 Faults = 21

HTML formatting here to break up/make a dividing row in between

January 2017 Errors = 22784
February 2017 Errors = 2650 

Using this foreach syntax:

foreach ($results as $result) :
    if ($result->id == 1){
        echo   '<td>', $result->Month, '</td>';

This works but I need to update the if statement, it is not a good solution

How can I change this so it looks inside the array and only outputs the HTML for each "id"?

I've tried foreach ($results =>id as $result) but it doesnt work. Is this the correct idea? What is the correct syntax?

THANKS!

Answer 1

I'm using this function from the array_multisort documentation. This should work for you. I've sorted the array to filter by the id. We save the id and if the next one contains it, we will output the html code.

    $results = array_msort($results , array('id'=>SORT_ASC));

    function array_msort($array, $cols){
      $colarr = array();
     foreach ($cols as $col => $order) {
         $colarr[$col] = array();
         foreach ($array as $k => $row) { $colarr[$col]['_'.$k] = strtolower($row[$col]); }
      }
      $eval = 'array_multisort(';
      foreach ($cols as $col => $order) {
          $eval .= '$colarr[\''.$col.'\'],'.$order.',';
       }
       $eval = substr($eval,0,-1).');';
       eval($eval);
       $ret = array();
       foreach ($colarr as $col => $arr) {
           foreach ($arr as $k => $v) {
               $k = substr($k,1);
              if (!isset($ret[$k])) $ret[$k] = $array[$k];
                $ret[$k][$col] = $array[$k][$col];
            }
       }
       return $ret;

    }

    $oldId = 0;
    foreach ($results as $res){
        if($oldId == $res->id){
             echo   '<td>', $res->Month, '</td>';
             //plus other output display
        }
        $oldId = $res->id;
    }