Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Unit 6 Unit 7 Unit 8 Unit 9
Unit 10
PHP Functions
To keep the browser from executing a script when the page loads, you can put your script into a function.A function will be executed by a call to the function. You may call a function from anywhere within a page.
Create a PHP Function
A function will be executed by a call to the function.
Syntax
function functionName()
{
code to be executed;
}
PHP function guidelines:
- Give the function a name that reflects what the function does
- The function name can start with a letter or underscore (not a number)
Example
A simple function that writes my name when it is called:
<html>
<body>
<?php
function writeName()
{
echo "Arbind Mandal";
}
echo "My name is "; writeName();
?>
</body>
</html>
Output: My name is Arbind Mandal.
PHP Functions – Adding parameters
To add more functionality to a function, we can add parameters. A parameter is just like a variable.Parameters are specified after the function name, inside the parentheses.
Example 1
The following example will write different first names, but equal last name:
<html>
<body>
<?php
function writeName($fname)
{
echo $fname . " Mandal.<br />";
}
echo "My name is "; writeName("Arbind Kumar"); echo "My sister's name is "; writeName("shreya");
echo "My brother's name is "; writeName("Manish");
?>
</body>
</html>
Output:
My name is Arbind Kumar Mandal
My sister’s name is Shreya Mandal
My brother’s name is Manish Mandal
Example 2
The following function has two parameters:
<html>
<body>
<?php
function writeName($fname,$punctuation)
{
echo $fname . " Mandal" . $punctuation . "<br />";
}
echo "My name is "; writeName("Arbind Kumar ",".");
echo "My sister's name is "; writeName("Shreya","!");
echo "My brother's name is "; writeName("Manish","?");
?>
</body>
</html>
Output:
My name isArbind Kumar Mandal.
My sister’s name is Shreya MAndal!
My brother’s name is Manish?
Pass by value
<?php
function addfive(&$num)
{
$num+=5;
}
function addsix(&$num)
{
$num+=6;
}
$orginum=10;
addfive($orginum);
echo "orginal value is :".$orginum."<br>";
addsix($orginum);
echo "orginal value is :".$orginum;
?>
Pass by reference
<?php
function addfive(&$num)
{
$num+=5;
}
function addsix(&$num)
{
$num+=6;
}
$orginum=10;
addfive($orginum);
echo "orginal value is :".$orginum."<br>";
addsix($orginum);
echo "orginal value is :".$orginum;
?>
WAP to store a information with an array displaying the value of array using function also display the no. of elements using an array
<?php
$age=array("Ram"=>20,"Hari"=>21,"Gita"=>22);
{function display($me)
asort($me);
foreach($me as $key=>$value)
{
echo " key : ".$key." value : ".$value."<br>";
}
$length=count($me);
echo "Total no of elements is :".$length;
}
display($age);
?>
PHP Functions – Return values
To let a function return a value, use the return statement.
<?php
function subnum($num,$num2)
{
$difference=$num-$num2;
return $difference;
}
$result=subnum(20,10);
echo "difference of two number :".$result."<br>";
function addnum($num,$num2)
{
$sum=$num+$num2;
return $sum;
}
$result1=addnum(5,10);
echo "sum of the two number :".$result1."<br>";
?>