Question

I have now a function like this

function checkInput($content, $emptyMessage = ""){
    if(isset($content)){ 
       return sanitize($content);
    }else{
       return $emptyMessage;
    }
 }

And I use it like this:

/* First get all data out of key and put it in array*/

//now check the input if user has set certain fields
$email = checkInput($user["email"],"No email address given");

echo $email;

Now I get: Uncaught ErrorOrWarningException.
I can think of two solutions:

Turning off errors > dont like that one.

Do manually for every field like

if(isset($user["email"])){ 
     $email = sanitize($user["email"]);
}else{
     $email =  "No email address given";
}
echo $email;

That sucks for readibility.
Another way would be to try / catch but thats almost the same length to type

Answer 1

When declaring a function with parameters, the parameter will always be set inside the function.

function checkInput($content, $emptyMessage = "") {
    // $content is always "set" here, no need for isset()

You’re getting a warning if you’re trying to access a non-existent variable here:

checkInput($user["email"], "No email address given");
  //       ^^^^^^^^^^^^^^
  // if 'email' is not set, a warning is thrown here

You’ll always need to make sure the "email" key is set before trying to pass its value into a function.

Having said that, that’s probably not the cause of your ErrorOrWarningException. I have no idea where that comes from, it’s not standard PHP. I suppose your sanitize function is throwing it. If so, you’ll need to try and catch inside your checkInput function.