Function for first test case fir checking numbers ending with st implemented.

Author: russom

Sprint-3/2-practice-tdd/get-ordinal-number.js

@@ -1,5 +1,10 @@
 function getOrdinalNumber(num) {
-  return "1st";
+  const lastDigit = num % 10;
+  const lastTwoDigits = num % 100;
+  if (lastDigit === 1 && lastTwoDigits !== 11) {
+    return `${num}st`;
+  }
+  return `${num}th`;
 }
 
 module.exports = getOrdinalNumber;