ECMAScript 6 String.prototype.endsWith() method can be used to check if a string ends with a suffix. But it is not yet supported by all browsers. Another approach is to use substring.
if (big.indexOf(small) == big.length-small.length) { ... }
Example – case sensitive string ends with check
<script> var big = "Hello World"; var small = "World"; if (big.substring(big.length-small.length, big.length) == small) { document.write("big string ends with small string"); } </script>
Example – string ends with check ignoring case
<script> var big = "hello World"; var small = "world"; if (big.toLowerCase().substring(big.length-small.length, big.length) == small.toLowerCase()) { document.write("big string ends with small string (ignoring case)"); } </script>