assigning value to a 2d array in foreach loop

Question

i have a 2d array

$arr = array (
array('x'=>'x1' , 'y'=>'') ,
array('x'=>'x2' , 'y'=>'') 
);

as you can see the y column is empty

if i want to put some value on it this doesn't works

foreach($arr as $a )
{
  if($a['x'] == 'x1')
   $a['y'] = 'y1';

  if($a['x'] == 'x2')
   $a['y'] = 'y2';
}

i know i can use 2 for loops , but i was wondering if there is a cleaner/simpler way like foreach to do this ? my application already uses the froeach loop to check some column in array and it's messy enough already i don't need 2 other loops !

Answer 1

The problem is you are using the array values instead of the keys. The following code will do it:

<?php
$arr = array (
array('x'=>'x1' , 'y'=>'') ,
array('x'=>'x2' , 'y'=>'') 
);
foreach($arr as $key => $value )
{
  if($arr[$key]['x'] == 'x1')
   $arr[$key]['y'] = 'y1';

  if($arr[$key]['x'] == 'x2')
   $arr[$key]['y'] = 'y2';
}
?>

As you can see, you should use the $key => $value notation for foreach.