PHP TUTORIALS - PHP Functions

PHP Functions

Creating PHP Function:


<html>
<head>
<title>Writing PHP Function</title>
</head>
<body>

<?php
/* Defining a PHP Function */
function writeMessage()
{
  echo "You are really a nice person, Have a nice time!";
}
/* Calling a PHP Function */
writeMessage();
?>
</body>
</html>

PHP Functions with Parameters:


<html>
<head>
<title>Writing PHP Function with Parameters</title>
</head>
<body>

<?php
function addFunction($num1, $num2)
{
  $sum = $num1 + $num2;
  echo "Sum of the two numbers is : $sum";
}
addFunction(10, 20);
?>
</body>
</html>


Sum of the two numbers is : 30

Passing Arguments by Reference:


<html>
<head>
<title>Passing Argument by Reference</title>
</head>
<body>
<?php
function addFive($num)
{
   $num += 5;
}

function addSix(&$num)
{
   $num += 6;
}
$orignum = 10;
addFive( &$orignum );
echo "Original Value is $orignum<br />";
addSix( $orignum );
echo "Original Value is $orignum<br />";
?>
</body>
</html>


Original Value is 15
Original Value is 21

PHP Functions retruning value:


<html>
<head>
<title>Writing PHP Function which returns value</title>
</head>
<body>

<?php
function addFunction($num1, $num2)
{
  $sum = $num1 + $num2;
  return $sum;
}
$return_value = addFunction(10, 20);
echo "Returned value from the function : $return_value
?>
</body>
</html>


Returned value from the function : 30

Setting Default Values for Function Parameters:


<html>
<head>
<title>Writing PHP Function which returns value</title>
</head>
<body>

<?php
function printMe($param = NULL)
{
   print $param;
}
printMe("This is test");
printMe();
?>

</body>
</html>


This is test

Dynamic Function Calls:


<html>
<head>
<title>Dynamic Function Calls</title>
</head>
<body>
<?php
function sayHello()
{
   echo "Hello<br />";
}
$function_holder = "sayHello";
$function_holder();
?>
</body>
</html>


Hello