Dynamic Function Calls

You can assign function names as strings to variables and then treat these variables exactly as you would the function name itself. Listing 6.5 creates a simple example of this.

Listing 6.5. Calling a Function Dynamically
 1: <!DOCTYPE html PUBLIC
 2:   "-//W3C//DTD XHTML 1.0 Strict//EN"
 3:   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
 4: <html>
 5: <head>
 6: <title>Listing 6.5 Calling a Function Dynamically</title>
 7: </head>
 8: <body>
 9: <div>
10: <?php
11: function sayHello() {
12:   print "hello<br />";
13: }
14: $function_holder = "sayHello";
15: $function_holder();
16: ?>
17: </div>
18: </body>
19: </html>

A string identical to the name of the sayHello() function is assigned to the $function_holder variable on ...

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