Does 0 count as empty php?

Code will explain more:

$var = 0;

if (!empty($var)){
echo "Its not empty";
} else {
echo "Its empty";
}

The result returns "Its empty". I thought empty() will check if I already set the variable and have value inside. Why it returns "Its empty"??

asked Feb 8, 2010 at 9:16

mysqllearnermysqllearner

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10

http://php.net/empty

The following things are considered to be empty:

• "" (an empty string)
• 0 (0 as an integer)
• 0.0 (0 as a float)
• "0" (0 as a string)
• NULL
• FALSE
• array() (an empty array)
• var $var; (a variable declared, but without a value in a class)

Note that this is exactly the same list as for a coercion to Boolean false. empty is simply !isset($var) || !$var. Try isset instead.

relipse

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answered Feb 8, 2010 at 9:18

15

I was wondering why nobody suggested the extremely handy Type comparison table. It answers every question about the common functions and compare operators.

A snippet:

Expression      | empty($x)
----------------+--------
$x = "";        | true    
$x = null       | true    
var $x;         | true    
$x is undefined | true    
$x = array();   | true    
$x = false;     | true    
$x = true;      | false   
$x = 1;         | false   
$x = 42;        | false   
$x = 0;         | true    
$x = -1;        | false   
$x = "1";       | false   
$x = "0";       | true    
$x = "-1";      | false   
$x = "php";     | false   
$x = "true";    | false   
$x = "false";   | false   

Along other cheatsheets, I always keep a hardcopy of this table on my desk in case I'm not sure

Pikamander2

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answered Feb 8, 2010 at 9:30

Dan SoapDan Soap

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1

In case of numeric values you should use is_numeric function:

$var = 0;

if (is_numeric($var))
{
  echo "Its not empty";
} 
else 
{
    echo "Its empty";
}

TerryA

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answered May 29, 2013 at 7:22

Khandad NiaziKhandad Niazi

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1

Use strlen() instead. I ran onto the same issue using 1/0 as possible values for some variables. I am using if (strlen($_POST['myValue']) == 0) to test if there is a character or not in my variable.

answered Aug 25, 2014 at 11:09

Calin RusuCalin Rusu

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4

I was recently caught with my pants down on this one as well. The issue we often deal with is unset variables - say a form element that may or may not have been there, but for many elements, 0 (or the string '0' which would come through the post more accurately, but still would be evaluated as "falsey") is a legitimate value say on a dropdown list.

using empty() first and then strlen() is your best best if you need this as well, as:

if(!empty($var) && strlen($var)){
    echo '"$var" is present and has a non-falsey value!';
}

answered Nov 10, 2015 at 12:21

Oliver WilliamsOliver Williams

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From a linguistic point of view empty has a meaning of without value. Like the others said you'll have to use isset() in order to check if a variable has been defined, which is what you do.

Giacomo1968

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answered Feb 8, 2010 at 9:32

Elzo ValugiElzo Valugi

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1

empty() returns true for everything that evaluates to FALSE, it is actually a 'not' (!) in disguise. I think you meant isset()

answered Feb 8, 2010 at 9:19

soulmergesoulmerge

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To accept 0 as a value in variable use isset

Check if variable is empty

$var = 0;

if ($var == '') {
    echo "empty";
} else {
    echo "not empty"; 
}
//output is empty

Check if variable is set

$var = 0;

if (isset($var)) {
    echo "not empty";
} else {    
    echo "empty";
}
//output is not empty

answered May 18, 2017 at 9:23

bhu1stbhu1st

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It 's working for me!

//
if(isset($_POST['post_var'])&&$_POST['post_var']!==''){
echo $_POST['post_var'];
}

//results:
1 if $_POST['post_var']='1'
0 if $_POST['post_var']='0'
skip if $_POST['post_var']=''

answered Aug 11, 2017 at 6:37

The following things are considered to be empty:

• "" (an empty string)
• 0 (0 as an integer)
• "0" (0 as a string)
• NULL
• FALSE
• array() (an empty array)
• var $var; (a variable declared, but without a value in a class)

From PHP Manual

In your case $var is 0, so empty($var) will return true, you are negating the result before testing it, so the else block will run giving "Its empty" as output.

answered Feb 8, 2010 at 9:19

codaddictcodaddict

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From manual: Returns FALSE if var has a non-empty and non-zero value.

The following things are considered to be empty:

• "" (an empty string)
• 0 (0 as an integer)
• "0" (0 as a string) NULL
• FALSE array() (an empty array) var
• $var; (a variable declared, but without a value in a class)

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

answered Feb 8, 2010 at 9:20

Adam KissAdam Kiss

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Actually isset just check if the variable sets or not.In this case if you want to check if your variable is really zero or empty you can use this example:

$myVar = '';
if (empty($myVar))
{
  echo "Its empty";
}
echo "<br/>";

if ($myVar===0)
{
  echo "also zero!";
}

just for notice $myVar==0 act like empty function.

Toon Krijthe

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answered Mar 8, 2011 at 7:17

arasharash

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if (empty($var) && $pieces[$var] != '0') {
//do something
}

In my case this code worked.

answered Jun 26, 2014 at 8:27

0

You need to use isset() to check whether value is set.

answered May 15, 2019 at 4:22

1

empty should mean empty .. whatever deceze says.

When I do

$var = '';    
$var = '0';

I expect that var_dump(empty($var)); will return false.

if you are checking things in an array you always have to do isset($var) first.

Saad

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answered Oct 13, 2017 at 18:07

use only ($_POST['input_field_name'])!=0 instead of !($_POST['input_field_name'])==0 then 0 is not treated as empty.

answered Jan 9, 2018 at 16:35

Not sure if there are still people looking for an explanation and a solution. The comments above say it all on the differences between TRUE / FALSE / 1 / 0.
I would just like to bring my 2 cents for the way to display the actual value.

BOOLEAN

If you're working with a Boolean datatype, you're looking for a TRUE vs. FALSE result; if you store it in MySQL, it will be stored as 1 resp. 0 (if I'm not mistaking, this is the same in your server's memory).

So to display the the value in PHP, you need to check if it is true (1) or false (0) and display whatever you want: "TRUE" or "FALSE" or possibly "1" or "0".
Attention, everything bigger (or different) than 0 will also be considered as TRUE in PHP. E.g.: 2, "abc", etc. will all return TRUE.

BIT, TINYINT

If you're working with a number datatype, the way it is stored is the same.
To display the value, you need to tell PHP to handle it as a number. The easiest way I found is to multiply it by 1.

answered Feb 17, 2019 at 19:55

proper example. just create int type field( example mobile number) in the database and submit an blank value for the following database through a form or just insert using SQL. what it will be saved in database 0 because it is int type and cannot be saved as blank or null. therefore it is empty but it will be saved as 0. so when you fetch data through PHP and check for the empty values. it is very useful and logically correct.

0.00, 0.000, 0.0000 .... 0.0...0 is also empty and the above example can also be used for storing different type of values in database like float, double, decimal( decimal have different variants like 0.000 and so on.

answered Mar 6, 2019 at 6:38

Sayed Mohd AliSayed Mohd Ali

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Is 0 considered empty PHP?

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