PHP Functions

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The real power of PHP comes from its functions. There are more than about 1000 built-in functions available in PHP, which is much enough to perform a lot of task.

PHP5 Functions

You are free to create your own functions (user-defined functions). A function is basically a block of code that can be used to perform some particular task in your program.

Create a Function in PHP

A function in PHP is created with the help of function keyword. Here is the general form to declare a function in PHP:

function functionName()
{
	code to be executed here;
}

Here, function is the keyword used in declaring the function in PHP, functionName is the name of the function. You can give a name to the function starting with a letter or underscore (but not with a number).

PHP Functions Example

Here is an example, creates a function named writeMsg(), to write a message as output:

<!DOCTYPE html>
<html>
<head>
	<title>PHP function Example</title>
</head>
<body>
<?php
	function writeMsg()
	{
		echo "This is PHP function tutorial.";
	}
	writeMsg();
?>
</body>
</html>

Here is the output produced by the above PHP script:

A function with parameters is known as parameterized function in PHP.

Here is another example, uses function with parameters in PHP:

<html>
<head>
	<title>Writing PHP Function with Parameters</title>
</head>
<body>
<?php
	function addFunction($num1, $num2)
	{
		$sum = $num1 + $num2;
		echo "Sum of the passed numbers is : $sum";
	}
	addFunction(100, 200);
?>
</body>
</html>

Here is the output of this PHP script:

Let's take another example also demonstrating functions in PHP with parameter.

<html>
<head>
	<title>Function Example in PHP</title>
</head>
<body>
<?php
	function printTable($num)
	{
		for($i=1;$i<=10;$i++)
		{
			echo $num*$i;
			echo " ";
		}
	}
	printTable(2);
	echo "<br/>";
	printTable(3);
	echo "<br/>";
	printTable(4);
	echo "<br/>";
?>
</body>
</html>

Here is the sample output produced by the above parameterized function in PHP example.

PHP Online Test

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