对PHP很新，检查以确保输入的数据对一大堆选项是好的

Hey there. I am writing some PHP that needs to check to see if a inputted value fits in with a whole bunch of options. What's the best way to hold all options to check against? I know that an array would work, but is there anything more efficent for this type of operation?

Checking if the input is a member of an array is actually a pretty safe and efficient way of securing it. For more complex checks, you may want to consider regular expressions with preg_match. However, regular expressions can easily become complicated. Also, one word of advice: Until you've modified the php interpreter, do not worry about of the efficiency of php commands except for loops and network code.

In many cases, you can actually accept anything and then encode it.

In PHP, all arrays are actually ordered maps, which means you can check keys really efficiently. All you really need for this is the keys, but I'm not sure how to make this without it. Maybe someone else knows how to make just a set.

// Setting the value to 1 is arbitrary since we're using isset
$valid_input = array('first valid option here' => 1,
                     'second valid option here' => 1,
                     'etc' => 1);

$input = // whatever
if(isset($valid_input[$input])) {
    // input is valid
}

References:

isset()

Arrays