PHP Functions

 PHP Functions

A function is a section of code that, when run, accomplishes a specified purpose. The primary rationale for utilizing functions is to reuse code; write once and run any time. When you need to write the same piece of code more than once in your application, we may utilize functions. You just need to create a function once, and then call it anytime you need it. In PHP, there are two sorts of functions.

• The function defined by the user
• built-in function

In this php tutorial, we will examine the first kind, which is user-created functions, and then we will go through some of the most essential inbuilt functions in PHP.

User-Specific Function

The function generated by the user is referred to as a user-defined function. The term "user-defined" refers to the fact that the function definition is written by the user.

Advantages

• It enables top-down modular programming.
• The program's length has been shortened.
• Once written, it can be used at any time.
• Working with user-defined functions necessitates the usage of two key components.

What is a User Defined Function?

Syntax

function function_name([parameters])
{
       Statements to be executed;
       [return value;]
}

Parameters are the optional inputs to your function; you can supply as many or as few as you wish. The return value indicates the output of your function when it is invoked; it is also optional.

The naming convention for functions is similar to that of variables in that it should begin with an underscore (_) or a letter, it should not contain any special characters, and it should not contain any keywords.

Function Call

Given is the syntax for calling a function.

function_name([Parameters if Any]);

Whenever you wish to run a specified function, you must call it with the appropriate arguments, and if the function returns a value, you must save the result. Let's have a look at a basic example.

For Ex.
<?php
        function Display()//function Definition
        {
                  echo "Hello DiscussDesk<br>";
        }
        Display();//function call
        Display();
?>

As you can see from the example, we first built a function named Display(), which accepts no parameters and has no return value. Later in our software, we invoked the Display() method twice, which executed the code twice.

Output

Hello DiscussDesk
Hello DiscussDesk

Function returning value

To return a value, add a return statement at the conclusion of the function body. The following is an example of this.

For Ex.
<?php
       function sum($a,$b)
       {
                 $c=$a+$b;
                 return $c;
       }
       echo "10 + 20 =".sum(10,20)."<br>";
       echo "10.30 + 20.30 =".sum(10.30,20.30)."<br>";
?>
Output
10 + 20 = 30
10.30 + 20.30 = 30.6

So, to summarize, in this session, we learned what php function is. Also covered is how to use a user-defined function in PHP.