How to check if a query string value is present via JavaScript?

Question

How can I check if the query string contains a q= in it using JavaScript or jQuery?

Answer 1

var field = 'q';
var url = window.location.href;
if(url.indexOf('?' + field + '=') != -1)
    return true;
else if(url.indexOf('&' + field + '=') != -1)
    return true;
return false