Currently you're working with the ternary operator:
$friendid = [!isset[$_GET['friendid']]] ? $_GET['friendid'] : 'empty';
Break it down to an if-else statement and it looks like this:
if[!isset[$_GET['friendid']]]
$friendid = $_GET['friendid'];
else
$friendid = 'empty';
Look at what's really happening in the if statement:
!isset[$_GET['friendid']]
Note the exclamation mark [!] in front of the isset function. It's another way to say, "the opposite of". What you're doing here is checking that there is no value already set in $_GET['friendid']. And if so, $friendid should take on that value.
But really, it
would break since $_GET['friendid'] doesn't even exist. And you can't take the value of something that isn't there.
Taking it from the start, you have set a value for $_GET['friendid'], so that first if condition is now false and passes it on to the else option.
In this case, set the value of the $friendid variable to empty.
What you want is to remove the exclamation and then the value of $friendid will take on the value of $_GET['friendid'] if it has been previously set.
PHP has two special shorthand conditional operators.
- Ternary Operator
- Null Coalescing Operator
PHP Ternary Operator
The ternary operator is a short way of performing an if conditional.
Ternary Syntax
[] ? [] : []
- If the condition is true, the result of on true expression is returned.
- If the condition is false, the result of on false expression is returned.
- Since PHP 5.3, you can omit the on true expression. [condition] ?: [on false] returns the result of condition if the condition is true. Otherwise, the result of on false expression is returned.
PHP Ternary Operator Example
Output:
pass
When do we use Ternary Operator?
We use ternary operator when we need to simplify if-else statements that are used to assign values to variables. Moreover, it is commonly used when we assign post data or validate forms.
Let’s say, we were programming a login form for a college university where we wanted to ensure that the user entered their registration number provided by the university then we could move further.
//if the registration number is not specified, notify the customer
$reg_number = [isset[$_POST['reg']]] ? $_POST['reg'] : die['Please enter your registration number'];
Let’s look at an example of a validation form for better understanding: