JS: String.prototype.endsWith

New in ES2015.

s.endsWith ( searchString )

s.endsWith ( searchString, endPosition )

Return true if s end with searchString. Else, returns false.

If endPosition is given, it is assumed to be the end of string. For example, "abcde".endsWith (str, 3) is the same as "abc".endsWith (str).

endPosition is negative, count from right.

const ss = "abcd";

console.log ( ss.endsWith("cd") ); // true
console.log ( ss.endsWith("cd", 4) ); // true
console.log ( ss.endsWith("a", 1) ); // true
console.log ( ss.endsWith("ab", 2) ); // true

console.log ( ss.endsWith("b") );  // false
console.log ( ss.endsWith("bc", 2) ); // false

Reference

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