PHP Tutorials By Vineet Kumar Saini

                                  Functions in PHP

Introduction

PHP is composed of a set of one or more functions. Functions divide large programs into
smaller, easier to handle pieces. Each function normally performs one specific task.
Functions are used to reduce the code in the programming i.e. reusability. Functions can be
placed anywhere in a page. PHP has more than 700 built-in functions.

Types of Functions

In this article I will describe only three types of functions, which are as follows:

      Simple Functions
      Functions with Parameter
      Functions with Return values

Simple Functions

A Simple function does not take any arguments (parameters) or values. The function name
should start with a letter or underscore (_), but not a number.

Syntax

  function functionName()
  {
    message ;
  }

Example

<?php
function CompnyName()
{
echo "MCN Solutions Pvt. Ltd. Noida.";
}
echo "My company name is ";
CompnyName();
?>

Output

In the above example we build a CompnyName() function and print a message inside this
function. This function is called later for printing the message.
PHP Tutorials By Vineet Kumar Saini




Functions with Parameter

We can add arguments (parameters) to a function. Using parameters, we can add more
functionally to a function. An argument is just like a variable of PHP. An argument
(parameter) is specified inside the parenthesis of a function.

Syntax

 function functionName (argument1,argument2)
 {
   message ;
 }

Example1

<?php
function CompnyName ($fullname) // one argument i.e. $fullname
{
echo $fullname;
}
echo "My company name is ";
CompnyName ("MCN Solutions Pvt. Ltd. Noida.");
?>

Output

In the above example we build a CompnyName() function and pass an argument as a
$fullname. This argument shows the message when you write a message in this function.
PHP Tutorials By Vineet Kumar Saini




Example2

<?php
function sum ($X, $Y) // two argument i.e. $X and $Y
{
$Z=$X + $Y;
echo "X=$X, Y=$Y, <br> Sum=$Z ";
}
sum(3,4);
?>

Output

In the above example we build a sum() function and pass two arguments as $X and $Y.
These arguments i.e. $X and $Y takes the values, when you pass the values in this function.
PHP Tutorials By Vineet Kumar Saini

Functions with Return values

In these types of functions, a function returns some values through the argument
(parameter). Remember that a function should return at least one value.

Example1

<?php
function sum ($X, $Y)
{
$Z=$X + $Y;
return $Z;
}
echo "The Sum of 3 and 4 = ".sum(3,4);
?>

Output

In the above example we build a sum() function and pass two arguments as $X and $Y.
Now we declare a variable $Z, which takes a sum of $X and $Y then we will return $Z.
Which shows the sum of X and y. In the above function we passed 3 and 4, which take by
$X and $Y and returns the sum of these value to the variable $Z.




Example2

<?php
function sum ($X, $Y)
{
$Z=$X + $Y;
return $Z;
}
$X=5;
$Y=7;
$Sum=sum ($X,$Y); // assign the value of Z to $Sum
PHP Tutorials By Vineet Kumar Saini

echo "The Sum of 5 and 7 = ".$Sum;
?>

Output

In the above example we build a sum() function and pass two arguments as $X and $Y.
Now we declare a variable $Z, which takes to sum of $X and $Y then we will return $Z.
Which shows the sum of X and y. In this example we assigned the value to $X and $Y i.e. 5
and 7 respectively. The sum of these values are returned by $Z to the $sum.




Conclusion

So in this article you saw types of functions and the use of functions in PHP. Using this
article one can easily understand the concept of functions in PHP.

Functions in PHP

  • 1.
    PHP Tutorials ByVineet Kumar Saini Functions in PHP Introduction PHP is composed of a set of one or more functions. Functions divide large programs into smaller, easier to handle pieces. Each function normally performs one specific task. Functions are used to reduce the code in the programming i.e. reusability. Functions can be placed anywhere in a page. PHP has more than 700 built-in functions. Types of Functions In this article I will describe only three types of functions, which are as follows:  Simple Functions  Functions with Parameter  Functions with Return values Simple Functions A Simple function does not take any arguments (parameters) or values. The function name should start with a letter or underscore (_), but not a number. Syntax function functionName() { message ; } Example <?php function CompnyName() { echo "MCN Solutions Pvt. Ltd. Noida."; } echo "My company name is "; CompnyName(); ?> Output In the above example we build a CompnyName() function and print a message inside this function. This function is called later for printing the message.
  • 2.
    PHP Tutorials ByVineet Kumar Saini Functions with Parameter We can add arguments (parameters) to a function. Using parameters, we can add more functionally to a function. An argument is just like a variable of PHP. An argument (parameter) is specified inside the parenthesis of a function. Syntax function functionName (argument1,argument2) { message ; } Example1 <?php function CompnyName ($fullname) // one argument i.e. $fullname { echo $fullname; } echo "My company name is "; CompnyName ("MCN Solutions Pvt. Ltd. Noida."); ?> Output In the above example we build a CompnyName() function and pass an argument as a $fullname. This argument shows the message when you write a message in this function.
  • 3.
    PHP Tutorials ByVineet Kumar Saini Example2 <?php function sum ($X, $Y) // two argument i.e. $X and $Y { $Z=$X + $Y; echo "X=$X, Y=$Y, <br> Sum=$Z "; } sum(3,4); ?> Output In the above example we build a sum() function and pass two arguments as $X and $Y. These arguments i.e. $X and $Y takes the values, when you pass the values in this function.
  • 4.
    PHP Tutorials ByVineet Kumar Saini Functions with Return values In these types of functions, a function returns some values through the argument (parameter). Remember that a function should return at least one value. Example1 <?php function sum ($X, $Y) { $Z=$X + $Y; return $Z; } echo "The Sum of 3 and 4 = ".sum(3,4); ?> Output In the above example we build a sum() function and pass two arguments as $X and $Y. Now we declare a variable $Z, which takes a sum of $X and $Y then we will return $Z. Which shows the sum of X and y. In the above function we passed 3 and 4, which take by $X and $Y and returns the sum of these value to the variable $Z. Example2 <?php function sum ($X, $Y) { $Z=$X + $Y; return $Z; } $X=5; $Y=7; $Sum=sum ($X,$Y); // assign the value of Z to $Sum
  • 5.
    PHP Tutorials ByVineet Kumar Saini echo "The Sum of 5 and 7 = ".$Sum; ?> Output In the above example we build a sum() function and pass two arguments as $X and $Y. Now we declare a variable $Z, which takes to sum of $X and $Y then we will return $Z. Which shows the sum of X and y. In this example we assigned the value to $X and $Y i.e. 5 and 7 respectively. The sum of these values are returned by $Z to the $sum. Conclusion So in this article you saw types of functions and the use of functions in PHP. Using this article one can easily understand the concept of functions in PHP.