php可以通过某些（服务器）错误跳过部分代码吗？

Question

Edit: I shall simplify my question: is it ever possible (maybe due to a server error) PHP skips a line (or part) of my code?

For example I have this code:

$number = 10;
$number += 6;
$number += 4;

echo $number;

Is it ever possible the number echoed is not 20, but 10, 16, or 14 because a line was skipped due to an error?

Answer 1

To answer your worries first. No there will be no point where a server error can cause your function return the opposite of expected result, as long as "A" is inside your array.

However, you seem to have done way too much coding for something that already exists.

You should use in_array:

$array = ["A", "F", "B", "G"]
if( in_array( "A", $array ) ) { 
    // Do stuff 
} else { 
    // Do something else 
}

If you want it to be case insensitive:

$array = ["A", "F", "B", "G"]
if( in_array( strtolower("A"), array_map('strtolower', $array) ) ) { 
    // Do stuff 
} else { 
    // Do something else 
}