{"id":242,"date":"2012-06-06T20:31:21","date_gmt":"2012-06-06T19:31:21","guid":{"rendered":"http:\/\/www.futuretrend.co.uk\/blog\/?p=242"},"modified":"2025-08-18T10:11:30","modified_gmt":"2025-08-18T09:11:30","slug":"a-very-gentle-introduction-to-php","status":"publish","type":"post","link":"https:\/\/www.futuretrend.co.uk\/blog\/a-very-gentle-introduction-to-php\/","title":{"rendered":"A very gentle introduction to PHP"},"content":{"rendered":"
\u00a0<\/span><\/div>\n
So what is PHP?<\/span><\/strong><\/div>\n
A Server side scripting language \u2013 code that is executed before the page loads (the opposite being client-side, JavaScript for example). \u00a0PHP can generate HTML and is often embedded directly with HTML to generate dynamic web pages.\u00a0<\/span><\/div>\n
\u00a0<\/span><\/div>\n
<?php\u00a0<\/span><\/div>\n
$question = \u2018Can we go on break now?;<\/span><\/div>\n
$time = 1045;<\/span><\/div>\n
$breaktime = 1100;<\/span><\/div>\n
\u00a0<\/span><\/div>\n
echo \u201c<h1>$question<\/h1>\u201d;<\/span><\/div>\n
\u00a0<\/span><\/div>\n
if ($time >= $breaktime) {<\/span><\/div>\n
echo \u201c<p>Good call, see you in five<\/p>\u201d;<\/span><\/div>\n
}<\/span><\/div>\n
else {<\/span><\/div>\n
echo \u201c<p>Computer says no<\/p>\u201d;<\/span><\/div>\n
}<\/span><\/div>\n
?><\/span><\/div>\n
\u00a0<\/span><\/div>\n
The server will then compute this script. Any ideas on what the output is?<\/span><\/div>\n
\u00a0<\/span><\/div>\n
Why PHP?<\/span><\/strong><\/div>\n
The snippet of code above demonstrated a conditional – You can automate what HTML is displayed based on certain conditions. You can also store variables<\/strong>, which allows for greater flexibility when writing web pages.<\/span><\/div>\n
\u00a0<\/span><\/div>\n
Who\u2019s using PHP?<\/span><\/strong><\/div>\n
Facebook, Twitter, Youtube, WordPress, Google, Yahoo, Wikipedia. Alernatives to PHP are asp.net (Microsoft Corp) JSP (Oracle) and Ruby (open source)<\/span><\/div>\n
\u00a0<\/span><\/div>\n
Arrays\u00a0<\/span><\/div>\n
The amount of data stored in websites these days is impressive \u2013 a typical website these days has usernames and passwords. To authenticate a user, you must match their password with the username. It is pretty easy to match two values together (hint: the conditional). Easy right? Yes! So how is it done\u2026?<\/span><\/div>\n
\u00a0<\/span><\/div>\n
Members\u2019 email addresses are stored in a database and we\u2019ll grab this information using PHP and store it in a variable (I\u2019ll explain this in more detail later) The code below demonstrates how to detect if the user actually exists:<\/span><\/div>\n
\u00a0<\/span><\/div>\n
<?php<\/span><\/div>\n
$members = array(\u2018John\u2019, \u2019Mary\u2019, \u2019Umi\u2019, \u2019Sarah\u2019, \u2018Lucy\u2019);<\/span><\/div>\n
$login = \u2018John\u2019;<\/span><\/div>\n
\u00a0<\/span><\/div>\n
foreach ($members as $member) {<\/span><\/div>\n
if ($member == \u2018$login\u2019) {<\/span><\/div>\n
echo \u201cHello $login\u201d;<\/span><\/div>\n
}<\/span><\/div>\n
}<\/span><\/div>\n
?><\/span><\/div>\n
\u00a0<\/span><\/div>\n
Now if you understood what went on above, well done! You\u2019ve just mastered the loop \u2013 the most essential part of programming! The syntax \u00a0for PHP arrays is: $members = array(\u2018John\u2019, \u2019Mary\u2019, \u2019Umi\u2019, \u2019Sarah\u2019, \u2018Lucy\u2019);<\/span><\/div>\n
\u00a0<\/span><\/div>\n
Items in an array are called elements<\/strong> and if I wanted to output the second element in this array:<\/span><\/div>\n
\u00a0<\/span><\/div>\n
<?php echo $members[1]; ?><\/span><\/div>\n
\u00a0<\/span><\/div>\n
That\u2019s no mistake. Array element [0] is the first element, [1] = second and so forth.<\/span><\/div>\n
\u00a0<\/span><\/div>\n
To print the entire array:<\/span><\/div>\n
\u00a0<\/span><\/div>\n
<?php print_r($members); ?><\/span><\/div>\n
Functions<\/span><\/strong><\/div>\n
echo and print_r are both functions. They do something to the arguments passed to them. The PHP language has many built-in functions and a developer can also write their own. Functions make code easier to read and allows for code re-use. Functions are a lot like people \u2013 you feed them something and then they spit something out in one way or another:<\/span><\/div>\n
\u00a0<\/span><\/div>\n
function a_human_being($food) {<\/span><\/div>\n
if ($food == tasty) {<\/span><\/div>\n
return \u2018burp\u2019;<\/span><\/div>\n
}<\/span><\/div>\n
else {<\/span><\/div>\n
return $food;<\/span><\/div>\n
}<\/span><\/div>\n
}<\/span><\/div>\n
\u00a0<\/span><\/div>\n
If you are confused at this point then give yourself a pat on the back for keeping up. It definitely takes time for the concepts to sink in and I guarantee that by the time you enrol on to the next PHP training course <\/a>you will be using these concepts as though you knew them all your life. You\u2019ll be making awesome websites in no time!<\/span><\/div>\n<\/span>
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