I have seen lots of jQuery examples where parameter size and name are unknown.
My URL is only going to ever have 1 string:
http://example.com?sent=ye
There is another example with using URI.js library.
Example answers the questions exactly as asked.
var url = 'http://example.com?sent=yes';
var urlParams = new URI(url).search(true);
// 1. Does sent exist?
var sendExists = urlParams.sent !== undefined;
// 2. Is it equal to "yes"?
var sendIsEqualtToYes = urlParams.sent == 'yes';
// output results in readable form
// not required for production
if (sendExists) {
console.log('Url has "sent" param, its value is "' + urlParams.sent + '"');
if (urlParams.sent == 'yes') {
console.log('"Sent" param is equal to "yes"');
} else {
console.log('"Sent" param is not equal to "yes"');
}
} else {
console.log('Url hasn\'t "sent" param');
}