[RESOLVED] Looping through an array

lerro

How can i loop through an array that contains fields returned from a table?

Do i use a "foreach" statement inside another "foreach" statement? and how would i access the field name and it's associated value during each loop?

NogDog

If it is a 2-dimensional array, then you can nest two levels of foreach():

foreach($myArray as $key => $row) {
   echo "<h3>$key</h3>\n<ul>\n";
   foreach($row as $field => $value) {
      echo "<li><b>$field:</b> $value</li>\n";
   }
   echo "</ul>\n";
}

lerro

I have tried that and i get the following error

Warning: Invalid argument supplied for foreach()

The error line it applies to is the second "foreach"

If a table has

           ID       Name     Surname

           1        Peter     Smith
           2        John       Mark

And these details are retrieved and put in an array, how would i get the "foreach" loop to loop through each record row and allow me to specify where to place the returned value?

e.g.

Loop through and display
{
$row['ID'] $row['Name'] $row['Surname']
}

bradgrafelman

How do you retrieve the data from the DB?

You probably only need a single foreach() per row, as you likely have a while() loop that is retrieving rows from the result set one-by-one.

lerro

The records are retrieved like this from another file that is a class


	$sql = "SELECT id, Name FROM tablename";

	$result = mysql_query($sql) or die(mysql_error());

	$result = mysql_fetch_array($result);

Then an attempt is made to output the array.

Would a while loop be needed in before "foreach" and how would i use the while loop to loop through an array? Do arrays have a way to detect end of array so that i could say "while not end of array"?

Derokorian

well generally I've seen

while( $row = mysql_fetch_array($result) ) {
    echo $row['name']; 
}

bradgrafelman

lerro wrote:
The records are retrieved like this

I think you mean record (singular), since you only retrieve the first row and ignore the rest. See the PHP manual page for [man]mysql_fetch_array/man for more info/examples of how the mysql_fetch_*() functions are used (e.g. often in a while() loop).

lerro wrote:
Would a while loop be needed in before "foreach"

See above.

lerro wrote:
how would i use the while loop to loop through an array?

You wouldn't - the while() loop would have nothing to do with looping through an array, but rather everything to do with repeteadly calling the mysql_fetch_*() function until all rows from the MySQL result set have been retrieved/processed.

lerro wrote:
Do arrays have a way to detect end of array so that i could say "while not end of array"?

Er... well yes, there is a way to tell if you're at the end of the array, but this is irrelevant in most cases - just use a foreach() loop instead and you don't need to worry about that.

lerro

Thanks