Well, the last lesson was on If...Else statements, this one will be on Functions.

Things you need to know
1.Basic PHP(Lesson 1)
2.I only speak English, sorry. So, everything will be in English terms.
3.I only put the stuff in quotes to be more organized. xD

Lesson #3;
Functions!

Questions & Answers
Q1.What is a function?
A1.A function is code that we can access at any time, such as the e-mail function; mailto(email@something.com).
Q2.Why use functions?
A2.Would you rather use
CODE
<?php

lots and lots of code
more code
more and more code

?>

or function()?


Making functions
1.To create a function, simple type function function_name() {
what it does;
}
2.Say I wanted to make a function that says "Astahost is the best host ever deal with it!", and named astahost(), it would look like this.
CODE
<?php
function astahost()
  {
  echo "Astahost is the best host ever deal with it!";
  }

astahost();
?>
[b]Output:[/b]
Astahost is the best host ever deal with it!
3.That was a fairly simple function, let's move onto something a bit more, not so simple.
[/quote]
[quote]
[b]More complex functions[/b]
1.Can have If...Else statements in it.
2.Making a function say different things.
[code]
<html>
<body>

<?php
function host($abc)
  {
  echo $abc . " is a great web host!<br />";
  }


host("AstaHost");

host("Trap17");
-
host("Computing Host");
?>

</body>
</html>

Output:
AstaHost is a great web host!
Trap17 is a great web host!
Computing Host is a great web host![/quote]
[quote]
How to use your own collection of functions
1.Simply create a file called functions.php, or anything else, just remember it.
2.Make your own functions on that file, xD.
3.Here is my math_functions.php
CODE
<?php
//adding
function add($x,$y)
  {
  $total = $x + $y;
   echo $total ."<br />";
  
  }

//subtracting
function subtract($x,$y)
  {
  $total = $x - $y;
   echo $total ."<br />";

  }

//multiplying
function multi($x,$y)
  {
  $total = $x * $y;
   echo $total ."<br />";

  }

//dividing
function divide($x,$y)
  {
  $total = $x / $y;
   echo $total ."<br />";

  }
?>

4.To use that in a page, simply do
CODE
<html>
<body>
<?php
include("math_functions.php"); ?>
<p>
4+4=
<?php
add(4,4); ?><br />
4-4=<?php
subtract(4,4); ?><br />
4*4=<?php
multi(4,4); ?><br />
4/4=<?php
divide(4,4); ?><br />
</p>
</body>
</html>
{had to separate them by ending the <?php over and over, the answer was not going where it should, lol}
Output:
4 + 4 = 8
4 - 4 = 0
4 * 4 = 16
4 / 4 = 1

Well, that's it. Next lesson will be on PHP forms, maybe.

 

 

 


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