array_search does not work as expected

Question

I have the following array :

$array = array (
    'a' => 'A',
    'b' => 'B',
    'c' => 'C'
);

I want to understand this behaviour :

// true, normal behaviour, there is a 'A' value in my array
echo array_search('A', $array) === 'a';

// true, normal behaviour, there is no 1 value in my array
echo array_search(1, $array) === false;

// true ???? there is no 0 as value in my array
echo array_search(0, $array) === 'a';

Why does array_search(0, $array) return the first key of my array?

Baba · Accepted Answer · 2012-11-12T15:54:11.467

6

FROM PHP DOC

If the third parameter strict is set to TRUE then the array_search() function will search for identical elements in the haystack. This means it will also check the types of the needle in the haystack, and objects must be the same instance.

Most people don't know array_search uses == by default If you want to search for identical element you need to add a strict parameter ... what do i mean ?

If you use

array_search(0, $array) //it would use == and 0 == 'A'

What you need is

array_search(0, $array,true) // it would compare with === 0 !== 'A'
                         ^------------ Strict

edited Nov 12 '12 at 15:54

answered Nov 12 '12 at 15:47

Baba

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I just checked, 'A' == 0 you're right. Strange behaviour. – Alain Tiemblo Nov 12 '12 at 15:50
`var_dump(0 == 'A');` would be `true` due to type conversion – Baba Nov 12 '12 at 15:51
The behavior is explained here: http://php.net/manual/en/language.operators.comparison.php (first example: `0 == "a"`) – Aziz Nov 12 '12 at 15:51
OK i remember it. That's like an `atoi` in C, "123string" will be converted to 123. That's ok! Thanks. – Alain Tiemblo Nov 12 '12 at 15:54
Yeah `var_dump(123 == "123string");` is true ..... – Baba Nov 12 '12 at 15:54
If you want to search for 0, put it in quotes: `array_search('0', $array,true)` – Peon Nov 12 '12 at 15:55
`var_dump("0" == "A");` would be false even without strict option – Baba Nov 12 '12 at 15:57

array_search does not work as expected

1 Answers1