Check if array key exists and is truthy in same command?

Question

In JavaScript, one can check myObject.key to see wether the value is there (not undefined) and truthy.

if (myObject.key) ...

Is there a PHP equivalent? Or do I have to keep writing code such as isset(my_array['key']) && my_array['key'] to acheive the desired result? I feel it violates DRY and looks ugly.

[`!empty(my_array['key'])` - http://php.net/manual/en/function.empty.php](http://php.net/manual/en/function.empty.php)? — Sean, Nov 15 '15 at 21:25
Just to put my two cents in: https://www.virendrachandak.com/techtalk/php-isset-vs-empty-vs-is_null/. Additionally, a similar [question has been asked](http://stackoverflow.com/questions/4559925/why-check-both-isset-and-empty) here on SO as well. — Jan, Nov 15 '15 at 21:26
@Sean Looks awesome. `empty` checks for 'falsyness', so negating it checks for 'truthyness', am I right? And this won't raise a notice if the key is not set? — Aviv Cohn, Nov 15 '15 at 21:31
@GinoPane I am more inclined to close a duplicate of [isset vs empty vs is_null](http://stackoverflow.com/questions/12375833/isset-vs-empty-vs-is-null) then to provide an answer. — Sean, Nov 15 '15 at 21:32
@AvivCohn yes, per the docs - [`empty() does not generate a warning if the variable does not exist`](http://php.net/manual/en/function.empty.php) — Sean, Nov 15 '15 at 21:34

score 15 · Accepted Answer · answered Nov 15 '15 at 21:30

15

There are three "levels" of checking in php:

array_key_exists($key, $array) - http://php.net/manual/en/function.array-key-exists.php

Checks if a key exists in an array. Returns true even if the value is null

isset($array[$key]) - http://php.net/manual/en/function.isset.php

Check if a key exists and is not null - Returns true if the value exists and is not null, but it can be bool(false), int(0), string "" and so on.

!empty($array[$key]) - http://php.net/manual/en/function.empty.php

Check if a key exists and is truthy, returns false for bool(false), int(0), non-existant keys and null, but true for bool(true), int(1), int(-1), string with length > 0 and so on. Actually the function it is empty(), but often used negated, too. This should be what you are searching for.

answered Nov 15 '15 at 21:30

clemens321

2,103
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Exactly, something to check for existence and truthyness. Thanks :) will accept. – Aviv Cohn Nov 15 '15 at 21:34
Empty is your best option here, because it will not complain if you pass it non-existant keys. – reggie Dec 03 '15 at 09:25
#2 is incorrect. `isset` returns false if the value is `null`. https://www.php.net/manual/en/function.isset.php – Sean the Bean Jan 22 '20 at 18:36
@Sean the bean: exactly what I said, "isset() returns true If key exists and is not null" => false if key does not exist, false if value is null, but true if it is e.g. 0, "", false, [] – clemens321 Jan 22 '20 at 21:12
@clemens321 Ah, right you are. I just got mixed up because of the indentation. – Sean the Bean Jan 28 '20 at 23:08

score -2 · Answer 2 · answered Dec 03 '15 at 09:24

-2

You could use the error suppression operator @:

if (@$_GET['fantasyvar']) {
    //$_GET['fantasyvar'] is set and truthy
}

Note: it's not good style and will make debugging more difficult for you.

answered Dec 03 '15 at 09:24

reggie

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14
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Check if array key exists and is truthy in same command?

2 Answers2