Converting user input string to regular expression

Question

I am designing a regular expression tester in HTML and JavaScript. The user will enter a regex, a string, and choose the function they want to test with (e.g. search, match,

Answer 1

In my case the user input somethimes was sorrounded by delimiters and sometimes not. therefore I added another case..

var regParts = inputstring.match(/^\/(.*?)\/([gim]*)$/);
if (regParts) {
    // the parsed pattern had delimiters and modifiers. handle them. 
    var regexp = new RegExp(regParts[1], regParts[2]);
} else {
    // we got pattern string without delimiters
    var regexp = new RegExp(inputstring);
}