update the code

Author: Alaa-Tagi

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

@@ -1,19 +1,22 @@
 function getOrdinalNumber(num) {
-    num = num.toString();
-    if (num.slice(-2) === '11' || num.slice(-2) === '12' || num.slice(-2) === '13') {
-        return num + 'th';
-    } else if (num.slice(-1) === '1') {
-        return num + 'st';
-    } else if (num.slice(-1) === '2') {
-        return num + 'nd';
-    } else if (num.slice(-1) === '3') {
-        return num + 'rd';
-    } else {
-        return num + 'th';
-    } 
+  num = num.toString();
+  const lastTwo = num.slice(-2);
+  const lastOne = num.slice(-1);
+
+  if (['11', '12', '13'].includes(lastTwo)) {
+    return num + 'th';
+  }
+
+  switch (lastOne) {
+    case '1': return num + 'st';
+    case '2': return num + 'nd';
+    case '3': return num + 'rd';
+    default:  return num + 'th';
+  }
 }
 
 module.exports = getOrdinalNumber;
+
 console.log(getOrdinalNumber(1));
 console.log(getOrdinalNumber(2));
 console.log(getOrdinalNumber(3));