Check whether an array is empty

Question

I have the following code

<?php

$error = array();
$error['something'] = false;
$error['somethingelse'] = false;

if (!empty($error))
{
    echo 'Error';
}
else
{
    echo 'No errors';
}

?>

However, empty($error) still returns true, even though nothing is set.

What's not right?

Works correctly for me in PHP 5.3 on Windows - I get `Error` — Pekka, Nov 30 '11 at 16:05
http://stackoverflow.com/questions/4139301/php-0-as-a-string-with-empty check answer no 2 — TheTechGuy, Nov 30 '11 at 16:06
What are you trying to achieve? When I run this code, I get Error which is correct because the array has keys and hence is not empty. Do you want false to somehow equate to "not there"? — liquorvicar, Nov 30 '11 at 16:11
I get Error too. I wanted it so that if $error['something'] = true, then only will $error return true. — gbhall, Nov 30 '11 at 16:16

score 425 · Accepted Answer · edited Apr 17 '15 at 00:02

425

There are two elements in array and this definitely doesn't mean that array is empty. As a quick workaround you can do following:

$errors = array_filter($errors);

if (!empty($errors)) {
}

array_filter() function's default behavior will remove all values from array which are equal to null, 0, '' or false.

Otherwise in your particular case empty() construct will always return true if there is at least one element even with "empty" value.

edited Apr 17 '15 at 00:02

blackbishop

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answered Nov 30 '11 at 16:04

ioseb

16,625
3
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2

array_filter($input) also removes empty arrays from $input. – jan Aug 19 '13 at 13:38
60

This could be trimmed down to `if (array_filter($errors)) {}` – Klemen Tusar Nov 20 '13 at 08:19
2

array_keys($errors, true) would do the same as this filter, I think. (Most people don't use the second argument, but you can search with it.) – grantwparks Dec 01 '13 at 04:22
or array_sum(array_values($errors)) would just tell you how many errors you have. – grantwparks Dec 01 '13 at 04:23

score 72 · Answer 2 · answered Nov 30 '11 at 16:06

72

You can also check it by doing.

if(count($array) > 0)
{
    echo 'Error';
}
else
{
    echo 'No Error';
}

answered Nov 30 '11 at 16:06

brenjt

15,997
13
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5

You don't need to count the elements or use empty(). A one-liner like php -r 'echo array() ? "T":"F";' will show the truthiness for an empty or non-empty array. – jerseyboy May 16 '14 at 13:08
empty() handles FALSE and isset(), so you may want empty() for that reason. – Brian Lewis Aug 21 '15 at 19:26

score 16 · Answer 3 · answered Nov 30 '11 at 16:05

16

Try to check it's size with sizeof if 0 no elements.

answered Nov 30 '11 at 16:05

0xd

1,891
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18

`sizeof` is an alias of `count`. – pmagunia Jun 28 '14 at 22:11
10

Reminder: `sizeof` is on the deprecation list, see https://wiki.php.net/rfc/deprecations_php_7_1 – Jens A. Koch Jul 28 '16 at 10:58
In this case, count (or sizeof) would return two, due to the two values which are set to false. – Bronzdragon Dec 03 '18 at 13:38

score 16 · Answer 4 · answered Nov 30 '11 at 16:12

PHP's built-in empty() function checks to see whether the variable is empty, null, false, or a representation of zero. It doesn't return true just because the value associated with an array entry is false, in this case the array has actual elements in it and that's all that's evaluated.

If you'd like to check whether a particular error condition is set to true in an associative array, you can use the array_keys() function to filter the keys that have their value set to true.

$set_errors = array_keys( $errors, true );

You can then use the empty() function to check whether this array is empty, simultaneously telling you whether there are errors and also which errors have occurred.

score 8 · Answer 5 · answered May 12 '15 at 21:27

8

array with zero elements converts to false

http://php.net/manual/en/language.types.boolean.php

answered May 12 '15 at 21:27

Eelco

111
1
5

score 5 · Answer 6 · answered Nov 30 '11 at 16:05

5

However, empty($error) still returns true, even though nothing is set.

That's not how empty() works. According to the manual, it will return true on an empty array only. Anything else wouldn't make sense.

answered Nov 30 '11 at 16:05

Pekka

442,112
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score 3 · Answer 7 · answered Nov 30 '11 at 16:05

3

From the PHP-documentation:

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 (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)

answered Nov 30 '11 at 16:05

David

209
1
6

Source http://php.net/manual/de/function.empty.php – user706420 Aug 11 '16 at 15:06

score 2 · Answer 8 · edited Oct 11 '12 at 16:26

2

function empty() does not work for testing empty arrays! example:

$a=array("","");
if(empty($a)) echo "empty";
else echo "not empty"; //this case is true

a function is necessary:

function is_array_empty($a){
foreach($a as $elm)
if(!empty($elm)) return false;
return true;
}

ok, this is a very old question :) , but i found this thread searching for a solution and i didnt find a good one.

bye (sorry for my english)

edited Oct 11 '12 at 16:26

karthikr

97,368
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answered Jul 15 '12 at 00:12

thewebsurfer

29
1

This is a best way of array empty checking. Or you can use $set_errors = array_keys( $errors, true ); – Kabir Hossain May 27 '15 at 05:25

score 2 · Answer 9 · edited Jun 07 '17 at 12:09

2

hi array is one object so it null type or blank

   <?php
        if($error!=null)
            echo "array is blank or null or not array";
    //OR
       if(!empty($error))
           echo "array is blank or null or not array";
    //OR
     if(is_array($error))
           echo "array is blank or null or not array";
   ?>

edited Jun 07 '17 at 12:09

Adrian Amigues

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1
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7

answered Nov 28 '14 at 12:20

Pulkit Ambliya

46
4

score 1 · Answer 10 · answered Dec 17 '14 at 01:30

In PHP, even if the individual items within an array or properties of an object are empty, the array or object will not evaluate to empty using the empty($subject) function. In other words, cobbling together a bunch of data that individually tests as "empty" creates a composite that is non-empty. Use the following PHP function to determine if the items in an array or properties of an object are empty:

function functionallyEmpty($o)
{
  if (empty($o)) return true;
  else if (is_numeric($o)) return false;
  else if (is_string($o)) return !strlen(trim($o)); 
  else if (is_object($o)) return functionallyEmpty((array)$o);

  // If it's an array!
  foreach($o as $element) 
    if (functionallyEmpty($element)) continue; 
    else return false; 

  // all good.
  return true;
}

Example Usage:

$subject = array('', '', '');

empty($subject); // returns false
functionallyEmpty($subject); // returns true

class $Subject {
    a => '',
    b => array()
}

$theSubject = new Subject();

empty($theSubject); // returns false
functionallyEmpty($theSubject); // returns true

This doesn’t work for at least inputs containing bool(true) values. Better write it like this: https://pastebin.com/DnFtDWgH — mermshaus, Apr 14 '17 at 22:40

score 1 · Answer 11 · answered Nov 30 '11 at 16:06

I can't replicate that (php 5.3.6):

php > $error = array();
php > $error['something'] = false;
php > $error['somethingelse'] = false;
php > var_dump(empty($error));
bool(false)

php > $error = array();
php > var_dump(empty($error));
bool(true)
php >

exactly where are you doing the empty() call that returns true?

score 1 · Answer 12 · answered Nov 30 '11 at 16:06

1

<?php
if(empty($myarray))
echo"true";
else
echo "false";
?>

answered Nov 30 '11 at 16:06

Vinit

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17
38

Check whether an array is empty

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