• php
  • 1661
  • 20-3-2008
    • The real power of PHP comes from its functions. In PHP - there are more than 700 built-in functions available. -------------------------------------------------------------------------------- [color=940306]PHP Functions[/color]
    In this tutorial we will show you how to create your own functions. -------------------------------------------------------------------------------- [color=940306]Create a PHP Function[/color]
    A function is a block of code that can be executed whenever we need it. Creating PHP functions: - All functions start with the word "function()"
    - Name the function - It should be possible to understand what the function does by its name. The name can start with a letter or underscore (not a number)
    - Add a "{" - The function code starts after the opening curly brace
    - Insert the function code
    - Add a "}" - The function is finished by a closing curly brace [color=940306]Example[/color]
    A simple function that writes my name when it is called:
    <html>
    <body>
    <?php
    function writeMyName()
    {
    echo "Kai Jim Refsnes";
    }writeMyName();
    ?>
    </body>
    </html>
    -------------------------------------------------------------------------------- [color=940306]Use a PHP Function[/color]
    Now we will use the function in a PHP script:
    <html>
    <body>
    <?php
    function writeMyName()
    {
    echo "Kai Jim Refsnes";
    }echo "Hello world!<br />";
    echo "My name is ";
    writeMyName();
    echo ".<br />That's right, ";
    writeMyName();
    echo " is my name.";
    ?>
    </body>
    </html>
    The output of the code above will be:
    Hello world!
    My name is Kai Jim Refsnes.
    That's right, Kai Jim Refsnes is my name.
    -------------------------------------------------------------------------------- [color=940306]PHP Functions - Adding parameters[/color]
    Our first function (writeMyName()) is a very simple function. It only writes a static string. To add more functionality to a function, we can add parameters. A parameter is just like a variable. You may have noticed the parentheses after the function name, like: writeMyName(). The parameters are specified inside the parentheses. [color=FA0309]Example 1[/color]
    The following example will write different first names, but the same last name:
    <html>
    <body>
    <?php
    function writeMyName($fname)
    {
    echo $fname . " Refsnes.<br />";
    }echo "My name is ";
    writeMyName("Kai Jim");echo "My name is ";
    writeMyName("Hege");echo "My name is ";
    writeMyName("Stale");
    ?>
    </body>
    </html>
    The output of the code above will be:
    My name is Kai Jim Refsnes.
    My name is Hege Refsnes.
    My name is Stale Refsnes.
    [color=FA0309]Example 2[/color]
    The following function has two parameters:
    <html>
    <body>
    <?php
    function writeMyName($fname,$punctuation)
    {
    echo $fname . " Refsnes" . $punctuation . "<br />";
    }echo "My name is ";
    writeMyName("Kai Jim",".");echo "My name is ";
    writeMyName("Hege","!");echo "My name is ";
    writeMyName("Ståle","...");
    ?>
    </body>
    </html>
    The output of the code above will be:
    My name is Kai Jim Refsnes.
    My name is Hege Refsnes!
    My name is Ståle Refsnes...


    -------------------------------------------------------------------------------- PHP Functions - Return values
    Functions can also be used to return values. [color=FA0309]Example[/color]
    <html>
    <body>
    <?php
    function add($x,$y)
    {
    $total = $x + $y;
    return $total;
    }echo "1 + 16 = " . add(1,16)
    ?>
    </body>
    </html>
    The output of the code above will be:
    1 + 16 = 17
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