en:web_development:media:named_arrays
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en:web_development:media:named_arrays [2021/12/25 13:48] mag created |
en:web_development:media:named_arrays [2023/08/16 09:33] (current) |
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| - | ====== Web Development Lesson | + | ====== Web Development Lesson |
| ===== Named Arrays ===== | ===== Named Arrays ===== | ||
| ==== Objective ==== | ==== Objective ==== | ||
| Line 37: | Line 37: | ||
| } | } | ||
| ?> | ?> | ||
| - | <!-- <img src=" | ||
| - | <img src=" | ||
| - | <img src=" | ||
| - | <img src=" | ||
| - | <img src=" | ||
| - | <img src=" | ||
| </ | </ | ||
| </ | </ | ||
| Line 160: | Line 154: | ||
| ==== Named Arrays ==== | ==== Named Arrays ==== | ||
| - | * We've seen how to create an array like this. | + | * We've seen how to create an array in PHP like this. |
| < | < | ||
| * This allows us to access each item in the array by number ($animals[0]). | * This allows us to access each item in the array by number ($animals[0]). | ||
| * For greater flexibility, | * For greater flexibility, | ||
| - | * Add the following code inside the first PHP block of ' | ||
| < | < | ||
| + | * Update the ' | ||
| + | < | ||
| + | "Photo 2" => " | ||
| + | "Photo 3" => " | ||
| + | "Photo 4" => " | ||
| + | "Photo 5" => " | ||
| + | "Photo 6" => " | ||
| ==== Displaying Arrays ==== | ==== Displaying Arrays ==== | ||
| * Now, let's display this inside the < | * Now, let's display this inside the < | ||
| - | <code> echo $animals;</code> | + | * <html>echo $photos;</html> won't work. When you view the page, you'll see the word ' |
| - | * This won't work. When you view the page, you'll see the word ' | + | |
| * Try this instead. | * Try this instead. | ||
| - | < | + | < |
| - | * < | + | * < |
| * When you view the page, you'll see some complicated text that looks something like the array. | * When you view the page, you'll see some complicated text that looks something like the array. | ||
| * To see it properly, right click on the page and select 'View Page Source' | * To see it properly, right click on the page and select 'View Page Source' | ||
| Line 182: | Line 181: | ||
| $animals[' | $animals[' | ||
| * We can read the array in the same way. Add this code to the < | * We can read the array in the same way. Add this code to the < | ||
| - | < | + | < |
| * Now view the page and check the results. | * Now view the page and check the results. | ||
| ==== Foreach ==== | ==== Foreach ==== | ||
| - | * We've seen how to do a 'for loop' in an earlier class, but there' | + | * We've seen how to do a 'for loop' in the previous activity, but there' |
| * Add the following PHP code to the < | * Add the following PHP code to the < | ||
| - | < | + | < |
| - | echo " | + | echo " |
| }</ | }</ | ||
| - | * The first line sets up the loop. It says 'run through this code for each item in the array < | + | * The first line sets up the loop. It says 'run through this code for each item in the array < |
| - | * We can now refer to the name and the actual item by using the variables < | + | * We can now refer to the name and the actual item by using the variables < |
| - | * < | + | * < |
| * Try it now to be sure you understand it. | * Try it now to be sure you understand it. | ||
| + | * When you're ready, add the following code to display the photos along with the respective names. | ||
| + | < | ||
| + | foreach($photos as $name => $link) { | ||
| + | ?> | ||
| + | < | ||
| + | <img src='<? | ||
| + | < | ||
| + | </ | ||
| + | <?php | ||
| + | } | ||
| + | ?></ | ||
| + | * There are a couple of things to note here. | ||
| + | * We've used a couple of new HTML tags. < | ||
| + | * Secondly, we've changed the way we encode the HTML block. Rather than include all the HTML inside a string, which requires us to add < | ||
| + | * This is much more readable for me. | ||
| + | * Refresh your page and check that it works as it should. | ||
| + | * It needs a bit of styling. Try this or add your own. | ||
| + | < | ||
| + | display: block; | ||
| + | text-align: center; | ||
| + | font-family: | ||
| + | color: green; | ||
| + | }</ | ||
| ==== While Loop ==== | ==== While Loop ==== | ||
| Line 213: | Line 235: | ||
| * So this is another way of running the same code multiple times. | * So this is another way of running the same code multiple times. | ||
| - | ==== Objects ==== | + | [[en: |
| - | * Objects are an advanced data structure and we won't go into it too much here, but you'll need to understand a little bit to use the PHP database connection. | + | |
| - | * An object is like a named array where you can access each element by name. | + | |
| - | * But an object also has functions built into. Recall that in Javascript < | + | |
| - | * Similarly, in PHP, an object can have both data and functions. For example, a database connection object can have information about the connection and also have functions to extract data. | + | |
| - | * Whereas you access the information in an array using < | + | |
| - | * To use an abstract example, we could create an object called $table. | + | |
| - | * We could set the number of legs on the table as follows. | + | |
| - | < | + | |
| - | * We could also move the table to another location as follows. | + | |
| - | < | + | |
| - | * There is a whole school of programming based on objects (Object-oriented programming) and objects could be the subject of many classes, but this is all you need to know to use the database connection. | + | |
| - | + | ||
| - | [[en: | + | |
en/web_development/media/named_arrays.1640468913.txt.gz · Last modified: 2023/08/16 09:33 (external edit)
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