Added getOrdinalNumber function

Author: khalidbih

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

@@ -1,5 +1,21 @@
-function getOrdinalNumber(num) {
-  return "1st";
+function getOrdinalNumber(num){
+  const lastTwoDigits = num % 100;
+  if (lastTwoDigits >= 11 && lastTwoDigits <= 13){
+    return num+ "th";
+  }
+  
+  const lastDigits = num %10;
+
+  switch (lastDigit){
+    case 1:
+      return num + "st";
+    case 2:
+      return num + "nd";
+    case 3:
+      return num + "rd";
+    default:
+      return num + "th";
+  }
 }
 
 module.exports = getOrdinalNumber;