questions

1.js

var string = "Alphabet";

function firstNonRepeatedCharacter(string) {
	var string = string.toLowerCase();
	for (var i = 0; i < string.length; i++) {
		var c = string.charAt(i);
		if (string.indexOf(c) == i && string.indexOf(c, i + 1) == -1) {
			return c;
		}
	}
	return null;
}
var result = firstNonRepeatedCharacter(string);
console.log( result );

2.sql

SELECT c.name, c.email FROM Customer as c, CustomerCreditCards as cc WHERE c.id = cc.customer_id AND cc.expirationdate BETWEEN DATE_SUB(NOW(), INTERVAL 14 DAY)

3.md

$("div a[target!='_blank"]").hide(); 

would fail, but:

$("div a[target!='_blank']").hide(); 

would work.

It would also hide option B:

<div>
	<a href="https:/www.google.com" target="_top">Clickme</a>
</div>