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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 PHP 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
  1. <?php  
  2. function CompnyName()  
  3. {  
  4. echo "MCN Solutions Pvt. Ltd. Noida.";  
  5. }   
  6. echo "My company name is ";  
  7. CompnyName();  
  8. ?>  
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.
 
image1.jpg 
 

PHP 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 ;
   }
 
Example 1
  1. <?php  
  2.  function CompnyName ($fullname) // one argument i.e. $fullname  
  3.  {  
  4.  echo $fullname;  
  5.  }  
  6.  echo "My company name is ";  
  7.  CompnyName ("MCN Solutions Pvt. Ltd. Noida.");  
  8.  ?>  
Output
 
In the above example we build a CompnyName() function and an argument as a $fullname. This argument shows the message when you write a message in this function.
 
image2.jpg 
 
Example 2
  1. <?php  
  2.  function sum ($X, $Y) // two argument i.e. $X and $Y  
  3.  {  
  4.  $Z=$X + $Y;  
  5.  echo "X=$X, Y=$Y, <br> Sum=$Z ";  
  6.  }  
  7.  sum(3,4);  
  8.  ?>  
Output
 
In the above example we build a sum() function and two arguments as $X and $Y. These arguments i.e. $X and $Y takes the values, when you the values in this function.
 
image3.jpg 
 

PHP 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.
 
Example 1
  1. <?php  
  2.  function sum ($X, $Y)  
  3.  {  
  4.  $Z=$X + $Y;  
  5.  return $Z;  
  6.  }  
  7.  echo "The Sum of 3 and 4  =  ".sum(3,4);  
  8.  ?>  
Output
 
In the above example we build a sum() function and 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 ed 3 and 4, which take by $X and $Y and returns the sum of these value to the variable $Z.
 
image41.jpg 
 
Example 2
  1. <?php  
  2.  function sum ($X, $Y)  
  3.  {  
  4.  $Z=$X + $Y;  
  5.  return $Z;  
  6.  }  
  7.  $X=5;  
  8.  $Y=7;  
  9.  $Sum=sum ($X,$Y);// assign the value of Z to $Sum  
  10.  echo "The Sum of 5 and 7  =  ".$Sum;  
  11.  ?>  
Output
 
In the above example we build a sum() function and 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.
 
image51.jpg 
 

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.
 
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