How to Check If $_Get Is Empty

How to check if $_GET is empty?

You said it yourself, check that it's empty:

if (empty($_GET)) {
    // no data passed by get
}

See, PHP is so straightforward. You may simply write, what you think ;)

This method is quite secure. !$_GET could give you an undefined variable E_NOTICE if $_GET was unset (not probable, but possible).

empty($_GET['variable']) blocks the script when the variable has no value

A blank page is a classic example of a PHP error. You need to set up and use PHP error logging facility like so:

error_reporting(E_ALL);
ini_set('display_errors', 1);

At the very top of your page.

Rewriting your page I would do this:

error_reporting(E_ALL);
ini_set('display_errors', 1);
if (!isset($_GET['a']) || is_null($_GET['a'])) {
    header("Location: https://google.com");
    exit();
}

echo "hello";

How do I check for an empty/undefined/null string in JavaScript?

Empty string, undefined, null, ...

To check for a truthy value:

if (strValue) {
    // strValue was non-empty string, true, 42, Infinity, [], ...
}

To check for a falsy value:

if (!strValue) {
    // strValue was empty string, false, 0, null, undefined, ...
}

---

Empty string (only!)

To check for exactly an empty string, compare for strict equality against "" using the === operator:

if (strValue === "") {
    // strValue was empty string
}

To check for not an empty string strictly, use the !== operator:

if (strValue !== "") {
    // strValue was not an empty string
}

check if variable empty

If you want to test whether a variable is really NULL, use the identity operator:

$user_id === NULL  // FALSE == NULL is true, FALSE === NULL is false
is_null($user_id)

If you want to check whether a variable is not set:

!isset($user_id)

Or if the variable is not empty, an empty string, zero, ..:

empty($user_id)

If you want to test whether a variable is not an empty string, ! will also be sufficient:

!$user_id

Laravel check if collection is empty

You can always count the collection. For example $mentor->intern->count() will return how many intern does a mentor have.

https://laravel.com/docs/5.2/collections#method-count

In your code you can do something like this

foreach($mentors as $mentor)
    @if($mentor->intern->count() > 0)
    @foreach($mentor->intern as $intern)
        <tr class="table-row-link" data-href="/werknemer/{!! $intern->employee->EmployeeId !!}">
            <td>{{ $intern->employee->FirstName }}</td>
            <td>{{  $intern->employee->LastName }}</td>
        </tr>
    @endforeach
    @else
        Mentor don't have any intern
    @endif
@endforeach

PHP - Check GET Variables Exist And Not Empty

You can just use empty which is a PHP function. It will automatically check if it exists and whether there is any data in it:

if(empty($var))
{
    // This variable is either not set or has nothing in it.
}

In your case, as you want to check AGAINST it being empty you can use:

if (!empty($u) && !empty($p))
{
    // You can continue...
}

Edit: Additionally the comparison !== will check for not equal to AND of the same type. While in this case GET/POST data are strings, so the use is correct (comparing to an empty string), be careful when using this. The normal PHP comparison for not equal to is !=.

Additional Edit: Actually, (amusingly) it is. Had you used a != to do the comparison, it would have worked. As the == and != operators perform a loose comparison, false == "" returns true - hence your if statement code of ($u != "" && $p != "") would have worked the way you expected.

<?php 
$var1=false;
$var2="";
$var3=0;

echo ($var1!=$var2)? "Not Equal" : "Equal";
echo ($var1!==$var2)? "Not Equal" : "Equal";

echo ($var1!=$var3)? "Not Equal" : "Equal";
echo ($var1!==$var3)? "Not Equal" : "Equal";

print_r($var1);
print_r($var2);
?>

// Output: Equal
// Output: Not Equal

// Output: Equal
// Output: Not Equal

Final edit: Change your condition in your if statement to:

if ($u != "" && $p != "")

It will work as you expected, it won't be the best way of doing it (nor the shortest) but it will work the way you intended.

Really the Final Edit:

Consider the following:

$u = isset($_GET["u"]); // Assuming GET is set, $u == TRUE
$p = isset($_GET["p"]); // Assuming GET is not set, $p == FALSE

Strict Comparisons:

if ($u !== "") 
// (TRUE !== "" - is not met. Strict Comparison used - As expected)

if ($p !== "")
// (FALSE !== "" - is not met. Strict Comparison used - Not as expected)

While the Loose Comparisons:

if ($u != "") 
// (TRUE != "" - is not met. Loose Comparison used - As expected)

if ($p != "")
// (FALSE != "" - is met. Loose Comparison used)

how to check if all the variable not empty in PHP

Like this:

$array = [
   'first_name' =>  'John',
    'last_name' => 'Doe',
    'email' => '',
];

if(count($array) != count(array_filter($array))){
    echo 'some rows are empty';
}

If you want to know which specific fields are empty you can use array_diff_key

$array = [
   'first_name' =>  'John',
    'last_name' => 'Doe',
    'email' => '',
];

$filled = array_filter($array);

if(count($array) != count($filled)){
    $empty = array_diff_key($array, $filled);
    echo 'field(s) '.implode(', ', array_keys($empty)).' are empty';
}

Ouputs:

field(s) email are empty

Obviously you can improve on the error string, or what have you. So in your case I would do something like this

if(count($array) != count($filled)){
    $empty = array_keys(array_diff_key($array, $filled));
    $last = '';
    if(count($empty) > 1 ){
       $last = ' and '.array_pop($empty);
    }
    $fields = implode(', ', $empty).$last; 
    echo json_encode(array('condition' => 'error','data' => 'Please fill in '.$fields));
}

So it should output something like this:

Please fill in email

Please fill in first_name and email

Please fill in first_name, last_name and email

You could even do:

$empty = array_map(function($item){
   return ucwords(str_replace('_', ' ', $item));
}, $empty);

Which would take, first_name and change it to First Name if you want to get fancy.

So... Putting all that togather:

$array = [
   'first_name' =>  '',
    'last_name' => '',
    'email' => '',
];

$filled = array_filter($array);

if(count($array) != count($filled)){
    $empty = array_map(function($item){
        return ucwords(str_replace('_', ' ', $item));
    },array_keys(array_diff_key($array, $filled)));
    $last = '';
    if(count($empty) > 1 ){
       $last = " and '".array_pop($empty)."'";
    }
    $fields = "'".implode("', '", $empty)."'".$last; 
    echo json_encode(['condition' => 'error','data' => 'Please fill in '.$fields]);
}

Outputs:

{"condition":"error","data":"Please fill in 'First Name', 'Last Name' and 'Email'"}

You can see it here live

And now it tells them exactly what fields they need, instead of some generic error.

HTTP GET: Check if var is empty

Use empty()

if(!empty($_GET['Field110'])){
    array_push($apnsarray, "E02");
}
// etc...

How do I check if a $_GET parameter exists but has no value?

Empty is correct. You want to use both is set and empty together

if(isset($_GET['app']) && !empty($_GET['app'])){
    echo "App = ".$_GET['app'];
} else {
    echo "App is empty";
}

---

Related Topics