Selecting different items in a fetch array - php

Question

When using mysql_fetch_array, i pass the array data to a separate variable. My question is how do i access the different items held in that array by their position?
Preferably i want to call each item in turn have a calculation run on that item and if the result is the lowest number so far, pass that data to a variable.
Any help is appreciated, thanks.
<?php
$query = "SELECT postcode FROM freelance ORDER BY id";
$result = mysql_query($query);
while($postcode = mysql_fetch_array($result)) {
echo "<span>" . $postcode['postcode'] . "</span></br>";
}
?>
Instead of echo out all postcodes how would i define to only output the third item in the array

Answer 1

Solution 1:
You can display them with a foreach in the while:
foreach($postcode as $data) {
echo $data;
}
Solution 2:
You can call them by position (starts with 0):
$postcode[0]
$postcode[1]
$postcode[2]
...
Read more about array's : http://www.php.net/manual/de/language.types.array.php

Answer 2

When you call mysql_fetch_array, you are getting the results of the next row returned by your query. In this case, your query is returning a result set with one column, postcode, and many rows (presumably). Your while loop is just getting each row's postcode value and echoing it in a <span>.
EDIT: I have changed my code example in reponse to the OP's comment.
I am not really familiar with what it is you are trying to do, but hopefully my example makes some sense (you will have to fill in some blanks with your code). For one, I don't think you need to store the results from the database into one big array and then go through each record to determine the lowest distance. You are already looping through each record in your while loop, make use of it!
<?php
$inputcoords = //I assume that you already have the coordinates for the input postal code somewhere
$query = "SELECT postcode FROM freelance ORDER BY id";
$result = mysql_query($query);
while($postcode = mysql_fetch_array($result)) {
$curpostcode = $postcode['postcode'];
$curcoords = //calculation/function/something that calculates the current coordinates from $curpostcode
$distance = //Haversine formula using $curcoords and $inputcoords (you'll have to figure this part out)
if (!isset($lowest) || $distance < $lowest) {
$lowest = $distance;
//optional: if you want to keep track of which postal code gave the shortest distance...
$lowestpostcode = $curpostcode;
}
}
//go on to use the calculated distances for something...
?>
Also, as a side note, mysql_* functions are deprecated. If at all possible, you should switch to mysqli or PDO.