Core PHP Programming, Third Edition

4.7. Dynamic Function Calls

You might find yourself in the position of not knowing which function should be called when you are writing a script. You want to decide based on data you have during execution. One way to accomplish this is to set a variable with the name of a function and then use the variable as if it were a function.

If you follow a variable with parentheses, the value of the variable will be treated as the name of a function. Listing 4.11 demonstrates this. Keep in mind that you can't refer to built-in functions in this way. Setting myFunction to be print will cause an error.

Listing 4.11. Calling a function dynamically

<?php function write($text) { print($text); } function writeBold($text) { print("<b>$text</b>"); } $myFunction ...