Workshop

True or false: If a function doesn't require an argument, you can omit the parentheses in the function call.

The statement is false. You must always include the parentheses in your function calls, whether you are passing arguments to the function or not.

How do you return a value from a function?

You must use the return keyword.

What would the following code fragment print to the browser?

$number = 50;

function tenTimes() {
    $number = $number * 10;
}

tenTimes();
print $number;

It would print 50. The tenTimes() function has no access to the global $number variable. When it is called, it will manipulate its own local $number variable.

What would the following code fragment print to the browser?

$number = 50;

function tenTimes() {
    global $number;
    $number = $number * 10;
}

tenTimes();
print $number;

It would print 500. We have used the global statement, which gives the tenTimes() function access to the $number variable.

What would the following code fragment print to the browser?

$number = 50;

function tenTimes( &$n ) {
    $n = $n * 10;
}

tenTimes($number);
print $number;

It would print 500. By adding the ampersand to the parameter variable $n, we ensure that this argument is passed by reference. $n and $number point to the same value, so any changes to $n will be reflected when you access $number.