Complete getOrdinalNumber implementation with Jest test cases

Author: Niangh-Ciang

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

@@ -1,5 +1,24 @@
 function getOrdinalNumber(num) {
-  return "1st";
+  const lastTwo = num % 100;
+  const lastOne = num % 10;
+
+  if (lastTwo === 11 || lastTwo === 12 || lastTwo === 13) {
+    return num + "th";
+  }
+
+  if (lastOne === 1) {
+    return num + "st";
+  }
+
+  if (lastOne === 2) {
+    return num + "nd";
+  }
+
+  if (lastOne === 3) {
+    return num + "rd";
+  }
+
+  return num + "th";
 }
 
 module.exports = getOrdinalNumber;

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

@@ -18,3 +18,33 @@ test("should append 'st' for numbers ending with 1, except those ending with 11"
   expect(getOrdinalNumber(21)).toEqual("21st");
   expect(getOrdinalNumber(131)).toEqual("131st");
 });
+
+// Case 2: Numbers ending with 2 (but not 12)
+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(102)).toEqual("102nd");
+});
+
+//Case 3: Number ending with 3 (but not 13)
+test("should append 'rd' for numbers ending with 3, except those ending with 13", () => {
+  expect(getOrdinalNumber(3)).toEqual("3rd");
+  expect(getOrdinalNumber(23)).toEqual("23rd");
+  expect(getOrdinalNumber(103)).toEqual("103rd");
+});
+
+//Case 4: Special cases: 11, 12, 13
+test("should append 'th' for special cases 11, 12, and 13", () => {
+  expect(getOrdinalNumber(11)).toEqual("11th");
+  expect(getOrdinalNumber(12)).toEqual("12th");
+  expect(getOrdinalNumber(13)).toEqual("13th");
+  expect(getOrdinalNumber(111)).toEqual("111th");
+  expect(getOrdinalNumber(112)).toEqual("112th");
+});
+
+//Case 5: All other numbers
+test("should append 'th' for all other numbers", () => {
+  expect(getOrdinalNumber(4)).toEqual("4th");
+  expect(getOrdinalNumber(20)).toEqual("20th");
+  expect(getOrdinalNumber(100)).toEqual("100th");
+});