Implement nd suffix

Author: Frumentius-Rev

practice-tdd/get-ordinal-number.js

@@ -1,3 +1,16 @@
 export function getOrdinalNumber(num) {
-  return `${num}st`;
+  const lastTwoDigits = num % 100;
+  const lastDigits = num % 10;
+
+  if (lastTwoDigits >= 11 && lastTwoDigits <= 13) {
+    return `${num}th`;
+  } else if (lastDigits === 1) {
+    return `${num}st`;
+  } else if (lastDigits === 2) {
+    return `${num}nd`;
+  } else if (lastDigits === 3) {
+    return `${num}rd`;
+  } else {
+    return `${num}th`;
+  }
 }

practice-tdd/get-ordinal-number.test.js

@@ -18,3 +18,9 @@ test("should append 'st' for numbers ending with 1, except those ending with 11"
   expect(getOrdinalNumber(21)).toEqual("21st");
   expect(getOrdinalNumber(131)).toEqual("131st");
 });
+
+test("should append 'nd' for numbers ending with 2, except those ending with 12", () => {
+  expect(getOrdinalNumber(2)).toEqual("2nd");
+  expect(getOrdinalNumber(22)).toEqual("22nd");
+  expect(getOrdinalNumber(112)).toEqual("112th");
+});