Regex to check whether string starts with, ignoring case differences

Question

I need to check whether a word starts with a particular substring ignoring the case differences. I have been doing this check using the following regex search pattern but th

Answer 1

You don't need a regular expression at all, just compare the strings:

if (stringToCheck.substr(0, query.length).toUpperCase() == query.toUpperCase())

Demo: http://jsfiddle.net/Guffa/AMD7V/

This also handles cases where you would need to escape characters to make the RegExp solution work, for example if query="4*5?" which would always match everything otherwise.