PHP Functions
A function is similar to a program that consists of a group of statements and perform a specific task. Functions are callable section of code in which you can pass data to and that function can return data to you.
Advantages of functions:
There are following advantages of functions.
- Functions are important in programming language like PHP, because they are used to perform calculations and perform any task which are required in software development.
- Functions are reusable. It means, once the function is written, it can be reused as and when required.
- Functions provides modularity for programming technique. And modular techniques help to break down a complex task into simpler task.
- Functions in a software development makes programmer easy to debug. Code maintenance becomes very easy.
- Features of any function can be changed without affecting the others functions.
- Using functions, you can reduce the length of the program.
Types of functions
There are two types of functions.
- Built-in functions
- User defined functions
Built-in functions
In PHP, there are over 1000 of built-in functions which are called directly to perform some task. These types of functions pre-defined within PHP.
User defined functions
Apart from built-in functions, you can create your own function.
- Functions name should starts with a letter or underscore followed by any numbers or letters.
- Function names are not case-sensitive.
- Functions are open by ‘{‘ and closed by ‘}’ curly braces.
How to create a user defined function in PHP?
A function in php defined with the word “function” followed by function name.
function function_name()
{
//Your code to be executed
...
}
Example- write a function to calculate sum of two numbers.
function sum()
{
a = 10;
b = 20;
sum = a+b;
echo sum;
}
//calling function
sum();
//result
30