User Defined Functions

The syntax to create a user defined function is:

function function_name(){

//statements here

}

You use the same naming conventions as you do for variables, without the dollar sign. Another rule to remember is to not use spaces when giving a name to a function. Otherwise it will be interpreted as two different words which will result in an error message. Use an underscore instead. Also, as a matter of good coding practice, it is good to give a representative name to a function. For example, set_name() would be a better function name than name1().

There are no limits as to how many statements can be included in the function. A function must include all the required elements, which are:

Function name

Opening and closing parentheses - ()

Opening and closing braces - {}

Statements
The actual formatting of the function itself is not important, as long as the above elements are included. You call the function by its name to execute it.

function_name();

The above will cause the statements in the function to be executed.

Let's create a function that generates a random password.

We will call the function randpass():

Script:createrndpass.php


function randpass()

$chars = "1234567890abcdefGHIJKLMNOPQRSTUVWxyzABCDEF
ghijklmnopqrstuvwXYZ1234567890";

$thepass = '';

for($i=0;$i<7;$i++)

{

$thepass .= $chars{rand() % 39};

}

return $thepass;

}

//to use the function

$password=randpass();

?>

The above function creates a password with random numbers and letters. The $chars variable contains letters and numbers that are mixed up. The content of that variable is then randomized with the rnd() function and a result is returned in the $thepass variable.

The "return $thepass;" part of the function returns the function result to whatever variable you want it in. Therefore to run this function, all we need to do is:

$password =randpass();