Weird array_search behaviour

Question

I have the following code:

<?php 

    $ray = array(1, "aa" , 0);
    echo "Index = " . array_search("I want to find this text", $ray);

?>

How to explain that the array_search() function returns existing index 2?

Answer 1

This is because array_search uses == to compare things. This makes PHP convert the operands so that their types match.

1 == "I want to find this text"
"aa" == "I want to find this text"
0 == "I want to find this text"

In the 1st and 3rd ones, PHP needs to convert "I want to find this text" to a number so it can compare. When converting a string to a number, PHP reads from the beginning of the string and stops at the first non-numeric character. So "I want to find this text" is converted to 0.

So the comparisons made are

1 == "I want to find this text" => 1 == 0 => false
"aa" == "I want to find this text" => false
0 == "I want to find this text" => 0 == 0 => true

And, that's why you get 2.

To fix this, do this: array_search("I want to find this text", $ray, true)

The 3rd parameter tells array_search to use === instead. This does not convert types, instead it compares them too. That will give you FALSE since nothing matches "I want to find this text" in both type and value.