CODEWITHSUNDEEP
phparraysreturnboolean
user3640967
user3640967

Reputation: 538

PHP "If true" test on array always returns true?

I have a validation function that I want to return true if the validation passes, or an array of errors if validation fails. However, when I check if the function returns true, it returns true even if the returned value is an array. Why is this? As a further example of what I mean:

$array = ['test' => 'test'];
if ($array == true)
  {
  echo 'true';
  }

and I also tried the same with a string:

$string = 'string';
if ($string == true)
  {
  echo 'true';
  }

And both echo true.

Why is this? And if we can do this then why do we need the isset() function?

Upvotes: 1

Views: 2437

Answers (1)

maxhb
maxhb

Reputation: 8865

This is expected behavior as documented in the manual http://php.net/manual/en/types.comparisons.php

Expression             gettype()  empty()   is_null()   isset() boolean
-----------------------------------------------------------------------
$x = array();          array      TRUE      FALSE       TRUE    FALSE
$x = array('a', 'b');  array      FALSE     FALSE       TRUE    TRUE
$x = "";               string     TRUE      FALSE       TRUE    FALSE
$x = "php";            string     FALSE     FALSE       TRUE    TRUE

So an empty string or array will evaluate to false and non empty strings or arrays will evaluate to true.

On the other hand isset() will determine if a variable is defined regardless of it's actual value. The only value being somehow different is null. A variable with value null will return false if tested with isset().

Upvotes: 5

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