PHP array_search consistently returns first key of array [duplicate]

Answer 1

If any key before the searched one is numeric zero, then that key is returned, because it is performing a "loose" match dominated by the array's data type, and "sharp" (if converted to int) counts as zero. Using a strict checking, the correct value is found.

Otherwise, by executing

$testcopy = array_map('strval', $testcopy);

so that values are translated to strings, it works also with "loose" check.

Answer 2

array_search is using == to compare values during search

FORM 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.

Becasue the first element is 0 the string was converted to 0 during search

Simple Test

var_dump("sharp" == 0); //true
var_dump("sharp" === 0); //false

Solution use strict option to search identical values

$testsharp = array_search("sharp", $testcopy,true);
                                               ^---- Strict Option

var_dump($testsharp);

Output

10

Answer 3

Welcome to the wonderful world of loose typing. In php, array_search defaults to nonstrict comparisons ("=="), but you can add a third parameter to force strict ("==="). You almost always want strict, though there are times when nonstrict is the correct operation.

check out the following:

$allcraftatts = array(0, 0, 0, 0, 0, 0, "Sharp Stone", "Sharp Stones", "stone", new stdClass(), "sharp", "hard", 0, 0, 0, 0, 0,0 ,0);
$testcopy=$allcraftatts;
$testsharp=array_search("sharp", $testcopy);
$testsharpStrict=array_search("sharp", $testcopy, true);

print_r(get_defined_vars());                                                                                                                                                                                                                        

if(0 == "sharp"){
    echo "true for == \n";
}else{
    echo "false == \n";
}
if(0 === "sharp"){
    echo "true for === \n";
}else{
    echo "false === \n";
}

and the output:

[testcopy] => Array
        (
            [0] => 0
            [1] => 0
            [2] => 0
            [3] => 0
            [4] => 0
            [5] => 0
            [6] => Sharp Stone
            [7] => Sharp Stones
            [8] => stone
            [9] => stdClass Object
                (
                )

            [10] => sharp
            [11] => hard
            [12] => 0
            [13] => 0
            [14] => 0
            [15] => 0
            [16] => 0
            [17] => 0
            [18] => 0
        )

    [testsharp] => 0
    [testsharpStrict] => 10
)
true for == 
false ===