Detecting if a variable is empty

Question

I have a variable of $message that when I echo displays nothing. Unfortunately the following code does not work.

if (!$message) {
    echo 'Nothing here!';
}

When I var_dump($message); I get the following:

string(48) ""

So it looks like somethings in there. Any ides?

Thanks,

John

So the string has a length of 48, is empty? How do you define `$message`? — Qirel, Mar 02 '17 at 15:42

score 1 · Answer 1 · answered Mar 02 '17 at 15:31

1

You could also use :

if($var == "")
{
    echo("nothing here");
}

answered Mar 02 '17 at 15:31

Adrien QUINT

43
6

score 1 · Answer 2 · edited May 23 '17 at 12:09

1

Use empty()

isset() will return true for empty value

What's the difference between 'isset()' and '!empty()' in PHP?

edited May 23 '17 at 12:09

Community

1
1

answered Mar 02 '17 at 15:33

Gerard

66
6

score 0 · Answer 3 · answered Mar 02 '17 at 15:31

0

use one of these:

http://php.net/manual/en/function.empty.php

if(isset($message)){
   echo "variable has value set";
}

if(!empty($message)){ 
   echo "Variable is empty";
}

answered Mar 02 '17 at 15:31

clearshot66

2,292
1
8
17

You have a slight logical error, `!empty()` means that it's not empty ;-) – Qirel Mar 02 '17 at 15:32

score 0 · Answer 4 · answered Mar 02 '17 at 15:31

0

Try this:

if(!$message || $message == "") {
   echo 'Nothing here!';
}

You can also use isset($message) or empty($message).

answered Mar 02 '17 at 15:31

Mark Knol

9,663
3
29
44

1

Or you can simplify it to `if (empty($message))` – Qirel Mar 02 '17 at 15:31

score 0 · Answer 5 · edited May 23 '17 at 12:09

0

When you are typing the name of your question, notice, that below many same questions could appear, like in this post, and you will not duplicate it then. For example, first post where you can find many answers: check if variable empty

And you save your time for typing question ;-)

edited May 23 '17 at 12:09

Community

1
1

answered Mar 02 '17 at 15:36

Marek Bernád

481
2
8
28

score 0 · Answer 6 · answered Mar 02 '17 at 15:41

Ok - I worked it out. I was building the $message variable with a load of MySQL queries and if there we're results displaying the in a table. I had a few tags outside of a if (mysqli_num_rows($result) <> 0) { } clause so they we're being saved in the variable.

Thanks all for your help anyway.

score 0 · Answer 7 · answered Mar 02 '17 at 15:44

You can use:

<?php
    is_null($var) //returns true if it's null

    empty($var) //returns true if it's empty

    isset($var) //returns true if it's not null.
?>

https://www.virendrachandak.com/techtalk/php-isset-vs-empty-vs-is_null/

I hope I've helped!

Detecting if a variable is empty

7 Answers7