Definition « Functions « PHP

1.Create function from string
2.Declaring a Simple Function
3.Function printing text on a Web Page
4.Declaring a Function
5.A Simple User Function
6.A Function Requiring Two Arguments
7.A Function to Build Query Strings
8.A function that calculates sales tax
9.Accessing a Global Variable from Within a Function

10.Build and then call a function
11.Call the function
12.Create a User Function
13.Defining functions before or after calling them
14.Creating and calling a function that accepts arguments
15.Define constant in a function
16.nesting functions key word in a function
18.Variables Defined Outside Functions Are Inaccessible from Within a Function by Default
19.Using nested functions