JS: String.prototype.charAt

s.charAt(pos)

Returns a string of length 1 that's the char at pos of s.

Return empty string if index is out of bound.

console.log ( "abc".charAt(1) === "b" ); // true

// if index is out of bound, return empty string
console.log ( "abc".charAt(9) === "" );
// true

Reference

ECMAScript 2015 §Text Processing#sec-string.prototype.charat