Implement getOrdinalNumber function to return correct ordinal suffixes

Author: MohammedNaru

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

@@ -1,5 +1,17 @@
 function getOrdinalNumber(num) {
-  return "1st";
+  const lastDigit = num % 10;
+  const lastTwoDigits = num % 100;
+
+  if (lastTwoDigits >= 11 && lastTwoDigits <= 13) {
+    return `${num}th`;
+  }
+
+
+  if (lastDigit === 1) return `${num}st`;
+  if (lastDigit === 2) return `${num}nd`;
+  if (lastDigit === 3) return `${num}rd`;
+
+  return `${num}th`;
 }
 
 module.exports = getOrdinalNumber;

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

@@ -1,13 +1,57 @@
-const getOrdinalNumber = require("./get-ordinal-number");
-// In this week's prep, we started implementing getOrdinalNumber
+// Case 2: Identify the ordinal number for 2
+// When the number is 2,
+// Then the function should return "2nd"
+test("should return '2nd' for 2", () => {
+  expect(getOrdinalNumber(2)).toEqual("2nd");
+});
+
+// Case 3: Identify the ordinal number for 3
+// When the number is 3,
+// Then the function should return "3rd"
+test("should return '3rd' for 3", () => {
+  expect(getOrdinalNumber(3)).toEqual("3rd");
+});
+
+// Case 4: Identify ordinal numbers ending in 1 but not 11
+// When the number ends with 1 but is not 11,
+// Then the function should return the correct 'st' suffix
+test("should return '21st' for 21", () => {
+  expect(getOrdinalNumber(21)).toEqual("21st");
+});
+
+// Case 5: Identify ordinal numbers ending in 2 but not 12
+// When the number ends with 2 but is not 12,
+// Then the function should return the correct 'nd' suffix
+test("should return '42nd' for 42", () => {
+  expect(getOrdinalNumber(42)).toEqual("42nd");
+});
 
-// continue testing and implementing getOrdinalNumber for additional cases
-// Write your tests using Jest - remember to run your tests often for continual feedback
+// Case 6: Identify ordinal numbers ending in 3 but not 13
+// When the number ends with 3 but is not 13,
+// Then the function should return the correct 'rd' suffix
+test("should return '53rd' for 53", () => {
+  expect(getOrdinalNumber(53)).toEqual("53rd");
+});
 
-// Case 1: Identify the ordinal number for 1
-// When the number is 1,
-// Then the function should return "1st"
+// Case 7: Identify teen exceptions 11, 12, 13
+// When the number is 11, 12, or 13,
+// Then the function should return the correct 'th' suffix
+test("should return '11th' for 11", () => {
+  expect(getOrdinalNumber(11)).toEqual("11th");
+});
+test("should return '12th' for 12", () => {
+  expect(getOrdinalNumber(12)).toEqual("12th");
+});
+test("should return '13th' for 13", () => {
+  expect(getOrdinalNumber(13)).toEqual("13th");
+});
 
-test("should return '1st' for 1", () => {
-  expect(getOrdinalNumber(1)).toEqual("1st");
+// Case 8: Identify general 'th' endings
+// When the number does not end in 1, 2, or 3 (except teens),
+// Then the function should return the 'th' suffix
+test("should return '20th' for 20", () => {
+  expect(getOrdinalNumber(20)).toEqual("20th");
+});
+test("should return '100th' for 100", () => {
+  expect(getOrdinalNumber(100)).toEqual("100th");
 });