You can use both DB fields and hard coded KEYs to build the array in a more defined fashion. Well instead of building the array with an open KEY, e.g. Please copy and paste and try to understand exactly what is happening With so little information and data it is difficult to know what is required but anyway this is how I would tackle the problem: [ If doing this in php was the best way (see the next point in this list), indexing/pivoting the data, using the rack_id values, rather than the zero referenced numerical index, when you fetch it, would allow you to directly access any related data, rather than to loop over all data to try and find it.Ĭ) Since this is related/relational data values, the ‘R’ in RDBMS, just do all of this in one query, then produce the output you want from the data that the query btext editor are you usintg? If you are unable to view variables or step through then… The way I read the example is that you want to get the matching ‘title’, and perhaps other values, out of $racks, for the current rack_id.ī) In your proposed code, the $key value is the numerical index, having nothing to do with the rack_id values. Show at least two pieces of data in the first array and show both matching and non-matching data in the second array. You would need to show enough example data and the result you expect from that data so that someone would know what you mean by ‘it loops through the second one as long as the key (Rack_Id) are the same’. You can now easily create code that works on entire arrays, reading or changing array values as you go.A) Your example doesn’t contain enough information to help you. Using references to alter array values as you loop through the array.How to access each element’s key and value within the loop.In this tutorial you’ve seen how to use PHP’s foreach construct to move through the elements in an array. In case you’re wondering, you can only change array values in a foreach loop. If you don’t delete the reference then you run the risk of accidentally referencing the last element in the array (“Lang, Fritz”) when you next use the $director variable, with often quite unexpected consequences! This is always a good idea if you think you might want to use the variable later in the script in a different context. Notice that the script calls unset() to delete the $director variable after it’s been used as a reference in the first loop. List( $firstName, $lastName ) = explode( ' ', $director ) Change the name format for each element to 'last, first' It’s a bit like a shortcut in Windows, or an alias in Mac OS.įor example, the following script loops through each director in the $directors array, and uses PHP’s explode() function and list construct to reverse the director’s first and last names: $value then becomes a reference to the element value in the original array, which means you can change the element by assigning a new value to $value.Ī reference is a pointer to the original value, rather than a copy of the value. You do this by placing an ampersand ( &) before the value variable in the foreach construct: To change array values, you need to reference the values. This is because foreach works on a copy of the array values, rather than the original array.

However, if you do this you’ll find that your array values aren’t changed. So far you’ve just looked at reading element values, but what if you want to change values as you loop through? You might try something like this: $movie = array( 'title' => 'Rear Window', Here’s an example that loops through an associative array of movie information, displaying each element’s key and value inside an HTML definition list:

Luckily, foreach gives you a way to do just that: So far so good, but what about associative arrays? With these types of arrays, you often want to access each element’s key as well as its value. The above script produces the following output: $directors = array( 'Alfred Hitchcock', 'Stanley Kubrick', 'Martin Scorsese', 'Fritz Lang' ) This code runs after the loop finishesįor example, the following script loops through a list of movie directors in an indexed array, displaying each director’s name as it goes:

The simplest way to use foreach is when looping through the values in an indexed array. In this article you learn the basic syntax of foreach, and see how to use it to loop through both indexed and associative arrays. However, there’s a much easier way to loop through arrays: the foreach construct. In Counting PHP Array Elements Using count(), I showed how you can use a for loop along with the count() function to loop through an array. For example, you may want to display each value in an HTML table, or give each element a new value. Often you need to move through all the elements in a PHP array so that you can do something with each element’s value.

For loop in php to display array