Sams Teach Yourself PHP, MySQL® and Apache All in One

Calling Functions

Functions come in two flavors—those built in to the language and those you define yourself. PHP has hundreds of built-in functions. Take a look at the following snippet for an example of a function use:

print ("Hello Web!");

In this example, we call the print() function, passing it the string "Hello Web!". The function then goes about the business of writing the string. A function call consists of the function name (print in this case) followed by parentheses. If you want to pass information to the function, you place it between these parentheses. A piece of information passed to a function in this way is called an argument. Some functions require that more than one argument be passed to them, separated by commas:

						some_function ...