Do the same - just with less code - php

Question

I've been trying to work my way to it simply must check it with all inputs in the present that I might have 100 lines so got it done less to just check it all together for an error or what?
What I think about that: instead of taking 14 lines of code that make it less but may be the same,
if($_POST["email"] == "")
{
$error = 1;
}
if($_POST["pass1"] == "")
{
$error = 1;
}
if($_POST["pass2"] == "")
{
$error = 1;
}
if($_POST["fornavn"] == "")
{
$error = 1;
}
if($_POST["efternavn"] == "")
{
$error = 1;
}
if($_FILES["file"] == "")
{
$error = 1;
}

Answer 1

Just create an array of field names and loop over them...
foreach(array('email','pass1','pass2',...) as $field) {
if(empty($_POST[$field])) {
$error = 1;
}
}
$_FILES you will have to handle separately. You can create another loop if you want. The structure of $_FILES is different though; I think you should be checking the "error" field. Check the docs.

Answer 2

Another way to approach this, considering the fact that you don't seem to be performing different tests for each field, or responding with specific error messages, is to use array_diff_key:
$names = array('email', 'pass1', 'pass2', 'fornavn', 'efternavn', 'file');
$names = array_keys($names); // convert $names to keys
$posts = array_filter($_POST); // filter out any falsy values
$fails = array_diff_key($names, $posts); // check for the differences
$error = $fail ? 1 : 0;
If you then wish to respond with specific messages depending on what is missing, you already have a list of the problem parameters in $fails. If you wish to extend the above to take into account specific value checks, you could write your own array filter callback function and pass it's name as the second parameter to array_filter... however this wont allow you to choose a different filter response based on array key, only on array value. All because rather annoyingly array_filter doesn't receive a key value when filtering an array.