Scotland | ITP JAN-2026 | Tuan Nguyen | Sprint 3 | 2- Practice-tdd

Sprint-3/2-practice-tdd/count.js

@@ -1,5 +1,33 @@
-function countChar(stringOfCharacters, findCharacter) {
-  return 5
+function countChar(fullString,findCharacters) {
+  let count = 0;
+  // both of these if statement is for input validation if the input not a string.
+  if( typeof findCharacters !== "string" || typeof fullString !== "string"){
+    throw new Error("Invalid input");
+  };
+
+  if (findCharacters.length < 1) {
+    throw new Error("findCharacters must be a single character");
+  }
+
+  for (let i = 0; i < fullString.length; i++){
+    if(fullString[i] === findCharacters){
+      count++;
+    }
+  }
+  return count;
 }
 
 module.exports = countChar;
+
+
+function assertTest(testInput,testCheck){
+ console.assert(
+  testInput === testCheck,
+  `Expect ${testInput} equal to ${testCheck}`
+ );
+};
+
+assertTest(countChar("whale fat hat cat","a"),4)
+assertTest(countChar("I need to lean more and know more","e"),5)
+assertTest(countChar("the city centre currently have a carnival","c"),4)
+assertTest(countChar("the cruise ship in in transit to south America","s"),4)

Sprint-3/2-practice-tdd/count.test.js

@@ -22,3 +22,6 @@ test("should count multiple occurrences of a character", () => {
 // And a character `char` that does not exist within `str`.
 // When the function is called with these inputs,
 // Then it should return 0, indicating that no occurrences of `char` were found.
+test( "should return count of zero occurrences of a character", () =>{
+   expect(countChar("go home and study","c")).toEqual(0)
+});

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

@@ -1,5 +1,50 @@
 function getOrdinalNumber(num) {
-  return "1st";
+// This is for num argument validation that go inside the function.
+if(typeof num !== "number" || Number.isNaN(num)){
+  throw new Error ("Invalid input: the value must be a number");
+}
+
+// This allow float number to be round into it nearest integer.
+num = Math.round(num);
+
+ if(num % 100 === 11 ||num % 100 === 12 || num % 100 === 13 ){
+  return `${num}th`;
+ }
+switch( true ){
+  case num % 10 === 1 : return `${num}st`;
+  case num % 10 === 2 : return `${num}nd`;
+  case num % 10 === 3 : return `${num}rd`;
+  default : return `${num}th`;
+}
 }
 
 module.exports = getOrdinalNumber;
+
+
+function testAssert (inputNumber,outputNUmber){
+console.assert(
+ inputNumber === outputNUmber,
+ `Test failed: expected ${outputNUmber}, but got ${inputNumber}`
+);
+};
+//Basic test of first digit integer
+testAssert(getOrdinalNumber(1), "1st");
+testAssert(getOrdinalNumber(2), "2nd");
+testAssert(getOrdinalNumber(3), "3rd");
+testAssert(getOrdinalNumber(4), "4th");
+//Test for 11, 12 and 13 
+testAssert(getOrdinalNumber(11), "11th");
+testAssert(getOrdinalNumber(12), "12th");
+testAssert(getOrdinalNumber(13), "13th");
+//Test for double digit number
+testAssert(getOrdinalNumber(21), "21st");
+testAssert(getOrdinalNumber(32), "32nd");
+testAssert(getOrdinalNumber(43), "43rd");
+//Normal number and float number test.
+testAssert(getOrdinalNumber(101), "101st");
+testAssert(getOrdinalNumber(202), "202nd");
+testAssert(getOrdinalNumber(1.2), "1st");   
+testAssert(getOrdinalNumber(10.51), "11th"); 
+
+
+

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

@@ -18,3 +18,64 @@ 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)
+// When the number ends with 2, except those ending with 12,
+// Then the function should return a string by appending "nd".
+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(142)).toEqual("142nd");
+});
+
+// Case 3: Numbers ending with 3 (but not 13)
+// When the number ends with 3, except those ending with 13,
+// Then the function should return a string by appending 'rd'.
+test("should append 'rd' for numbers ending with 3, except those ending with 13", () => {
+  expect(getOrdinalNumber(3)).toEqual("3rd");
+  expect(getOrdinalNumber(33)).toEqual("33rd");
+  expect(getOrdinalNumber(153)).toEqual("153rd");
+});
+
+// Case 4: Special cases 11, 12, 13
+// When the number ends with 11, 12, or 13,
+// Then the function should always append "th".
+test("should append 'th' for special cases 11, 12, 13", () => {
+  expect(getOrdinalNumber(11)).toEqual("11th");
+  expect(getOrdinalNumber(12)).toEqual("12th");
+  expect(getOrdinalNumber(13)).toEqual("13th");
+  expect(getOrdinalNumber(111)).toEqual("111th");
+  expect(getOrdinalNumber(212)).toEqual("212th");
+});
+
+// Case 5: All other numbers
+// When the number does not end with 1, 2, or 3,
+// Then the function should append "th".
+test("should append 'th' for all other numbers", () => {
+  expect(getOrdinalNumber(4)).toEqual("4th");
+  expect(getOrdinalNumber(10)).toEqual("10th");
+  expect(getOrdinalNumber(100)).toEqual("100th");
+  expect(getOrdinalNumber(204)).toEqual("204th");
+});
+
+// Case 6: Float numbers should be rounded to nearest integer
+// When the input is a float,
+// Then the function should round it and return the correct ordinal.
+test("should round float numbers and return correct ordinal", () => {
+  expect(getOrdinalNumber(1.2)).toEqual("1st");   // rounds to 1
+  expect(getOrdinalNumber(1.8)).toEqual("2nd");   // rounds to 2
+  expect(getOrdinalNumber(2.5)).toEqual("3rd");   // rounds to 3
+  expect(getOrdinalNumber(10.51)).toEqual("11th"); // rounds to 11
+  expect(getOrdinalNumber(12.49)).toEqual("12th"); // rounds to 12
+  expect(getOrdinalNumber(12.5)).toEqual("13th");  // rounds to 13
+});
+
+// Case 7: Invalid inputs should throw an error
+// When the input is not a number,
+// Then the function should throw an error.
+test("should throw an error for invalid inputs", () => {
+  expect(() => getOrdinalNumber("10")).toThrow("Invalid input");
+  expect(() => getOrdinalNumber(null)).toThrow("Invalid input");
+  expect(() => getOrdinalNumber(undefined)).toThrow("Invalid input");
+  expect(() => getOrdinalNumber(NaN)).toThrow("Invalid input");
+});