June 5th, 2019 
Nilesh Chaurasia PHP User Defined Functions
PHP User Defined functions mean that a function which is created by a user. The declaration of the user-defined function will start with the “function” keyword.
Syntax of PHP user defined function deceleration
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<?php
function functionName()
{
code to be execute;
}
?>
</body>
</html>
Note: The name of the function must be started with a character and underscore not to be with number.
Example 1 – User Defined Functions Example
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<?php
function info() // creating a function
{
echo "Welcome to the Technology World";
}
info(); // calling of function
?>
</body>
</html>
In the above example we exaplain how you can create a function and how you cann use this function.
Here we create a function with the name “info()” and this function have some return value. And last we call this function. The below screenshot is the result of the above code.
PHP Function Parameters or Arguments
The argument is not another thing it is just like a variable. When you pass some parameter or value inside the braces this is called Function Parameters or Arguments.
Example 2 – User defined function example with Parameters or Arguments
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<?php
function cal($x,$y) // creating a function
{
echo "The value of x is " . $x . " " . "& y is " . $y . "<br />";
}
cal(5,6);
cal(87,6);
cal(98,82);
?>
</body>
</html>
In the above example, we create a function is cal and have 2 arguments $x and $y and the function cal is used to print the value of $x and $y.
Caution:You can add many arguments as your requirement but you have to separate with a comma “,” symbol.
PHP Function Return a Value
PHP Function Return means that a function returns a value. And to return a value you have to use the “return” keyword.
Example 3 – User defined function example with return value
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<?php
function sq($x) // creating a function
{
$z= $x * $x;
return($z);
}
echo sq(65) . " is the square of 65" . "<br />";
echo sq(74) . " is the square of 74" . "<br />";
echo sq(87) . " is the square of 87" . "<br />";
echo sq(73) . " is the square of 73" . "<br />";
?>
</body>
</html>
In the above example, we create a function sq() and this function calculates the square of a number. In this function, we write the calculation of a square.
PHP Factorial Function
Example 4 – PHP Factorial Function Code return the calculated factorial value
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<?php
function fact($x) // creating a function
{
$fact1=1;
for($i=1; $i<=$x; $i++)
{
$fact1 = $fact1 * $i;
}
return $fact1;
}
echo fact(5) . " is the factorial of 5" . "<br />";
echo fact(6) . " is the factorial of 6" . "<br />";
echo fact(7) . " is the factorial of 7" . "<br />";
echo fact(13) . " is the factorial of 13" . "<br />";
?>
</body>
</html>
In the above example, we create a function fact() and this function calculates the factorial of a number($x).
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