Question

How do I force section to be either asd or alg or sys or data or sim or se ?

If I use regex like below, then datadfghdg would be allowed.

if (section == '') {
    alert('Section is required');
} else if (!(/asd|alg|sys|data|img|se/.test(section))) {
    alert('Section must be one of: asd alg sys data img se');
} else {
    is_okay = 1;
}

Answer 1

You can force the strings to be at the beginning and and of the regex by using ^ and ^$` respectively:

if( !(/^(asd|alg|sys|data|img|se)$/.test(section)) )
    ...

Alternatively you can use in to achieve this as well:

if( section in { 'asd':'','alg':'', ... } )
    ...