In php is 0 treated as empty

Question

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

empty   returns true for everything that evaluates to FALSE  it is actually a  not      in disguise  I think you meant isset

User · Answer

use only    POST  input field name     0 instead of     POST  input field name     0 then 0 is not treated as empty

User · Answer

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   amp  amp  strlen  var        echo    var  is present and has a non-falsey value

User · Answer

You need to use isset   to check whether value is set

User · Answer

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   quot TRUE quot  or  quot FALSE quot  or possibly  quot 1 quot  or  quot 0 quot   Attention  everything bigger  or different  than 0 will also be considered as TRUE in PHP  E g   2   quot abc quot   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

User · Answer

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   lt br  gt     if   myVar   0      echo  also zero        just for notice  myVar  0 act like empty function

User · Answer

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

User · Answer

if  empty  var   amp  amp   pieces  var      0       do something     In my case this code worked

User · Answer

It  s working for me      if isset   POST  post var    amp  amp   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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

[php] In php, is 0 treated as empty?

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