in_array在数组中找不到值

Question

I have an array formed by exploding a string as follows.

$interest_array = explode(',', $user->interests);

When I var_dump this array I get

array(3) { 
    [0]=> string(19) "Acute critical care" 
    [1]=> string(11) " Cardiology" 
    [2]=> string(20) " Computed Tomography"
}

With the following code

if (in_array('Acute critical care', $interest_array)) {
        echo "selected";}

I output....selected. Now thats fine, but I need this to work for several of the array values. With the following code for example,

if (in_array('Acute critical care', $interest_array)) {
    echo "selected_once";
}

if (in_array('Cardiology', $interest_array)) {
    echo "selected_twice";
}

I only get one output of selected once , but I am expecting an output of selected once twice .

Why is this. I have seen that many people have had similar issues with in_array but none of the solutions I have found work (and most of the questions are slightly different. I have tried flipping the array and using array_key_exists without luck. I have also tried preg_replace to remove the white space within the string without luck. Can someone explain what the issue is?

Answer 1

If you look the var_dump() output carefully, you can see that the string Cardiology has a space at the beginning:

string(11) " Cardiology"
            ^

This is causing in_array() to not detect it as a matching value. To remove the space, you could apply trim on all the array elements using array_map() before doing the in_array() check:

$interest_array = explode(',', $user->interests);
$interest_array = array_map('trim', $interest_array);