PHP中的Strcmp和字符串比较，其中字符串来自数组

Here's what I'm trying to achieve, which at the moment returns "error", despite $assign holding the value A.

if ($assign === "A") {
    echo "Assign is A";
}
    elseif ($assign === "B") {
        echo "Assign is B";
}
    else {
        echo "error";
}

$assign is getting its value from an array, as shown below where I checked anything I could think of. The strcmp below returns -52, which has me stumped. $assignments[0] definitely holds "A", without any extraneous spaces or characters, and the type is definitely string.

$assign = $assignments[0];
print_r ($assign);
print (gettype($assign));
echo strcmp ($assign, "A");

I'm assuming that the issue is that I'm not assigning $assign the value "A" but instead some sort of reference to it as it comes from an array, but I'm afraid that's as far as my troubleshooting has gotten me!