Page 185 - Beginning PHP 5.3

Chapter 7: Functions
Save this script as hello_with_style.php in your document root folder and try it out. The resulting
page is shown in Figure 7 - 2 . You can see how the same line of code within the function is used three
times to produce three quite different - looking greetings.

Figure 7-2

Optional Parameters and Default Values

The preceding hello_with_style.php script shows that functions can be pretty powerful. The single -
line function within the script, helloWithStyle() , is capable of displaying the text “ Hello, world! ”
using any font and text size supported by the user ’ s browser.
However, suppose that most of the time you wanted to use a font size of 1.5 em. It would be tiresome to
have to include the second argument each time you called the function:
helloWithStyle( “Helvetica”, 1.5 );
helloWithStyle( “Times”, 1.5 );
helloWithStyle( “Courier”, 1.5 );

Fortunately, PHP lets you create functions with optional parameters. You define an optional parameter
as follows:

function myFunc( $parameterName=defaultValue ) {
// (do stuff here)
}

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