undefined offset

[garry27]

i'm tring to create a new array called $location which will consist of the values of two other arrays $longitude and $latitude (both of which have an equal number of values) joined together in asingle string (plus the comma). am i doing this right because i keep getting errors saying "undefined offset...in line 31"


[code]

$result = count($longitude);
for ( $i = 0; $i <$result; $i++ ) {
    $location[$i] = array ( $longitude[$i].','.$latitude[$i] );      //line 31
}[/code]

[Daniel0]

Try this instead: [code]<?php
$result = count($longitude);
$location = array();
for($i=0; $i<$result; $i++)
{
$location[] = "{$longitude[$i]},{$litatude[$i]}";
}
?>[/code]

Note that somethings was just changed to fit my coding style, what I think caused the error was that $location was not an array.

[garry27]

i still get the same error. here's the code from the start of the function:

[code]function a(){
  $sql = mysql_query ( "select Longitude from Pubs" );
  $longitude = mysql_fetch_array($sql);
  if (!$sql){
  die('Invalid query: ' . mysql_error());
  }
  $sql = mysql_query ( "select Latitude from Pubs" );
  $latitude = mysql_fetch_array($sql);
  if (!$sql){
  die('Invalid query: ' . mysql_error());
  }
 
 
  $result = count($longitude);
$location = array();
for($i=0; $i<$result; $i++)
{
$location[] = "{$longitude[$i]},{$latitude[$i]}";
}[/code]

did you mean to leave the index value blank for location inside the loop? i get the same error messages both ways anyway  :-\

cheers for the help

[btherl]

"undefined offset" means you are trying to access an array element that doesn't exist.

It's likely that your latitude and longitude don't have the same number of elements.  To check, use count() on both of them and see if the numbers match up.

Are you intending to fetch several rows of data from your sql queries, or just a single row with many columns?  mysql_fetch_array() will only fetch a single row.  That may also be causing problems.

[garry27]

yes, the numbers match up but i'm also trying to fetch several rows. is there a built in function or some other way i can do this?  :)

[alpine]

Try:
[code]

<?php

function a(){
$sql = mysql_query ("select Longitude,Latitude from Pubs") or die('Invalid query: ' . mysql_error());
$location = array();
while($elements = mysql_fetch_array($sql))
{
$location[] = $elements[0].",".$elements[1];
}
return $location;
}


echo "<pre>";
print_r(a());
echo "</pre>";

?>

[/code]

[garry27]

that's great!

thanks for all the advice, fellas.