West Midlands | ITP September 2025 | Jonathan Boahene | Sprint 2 | Module Structuring and Testing Data

Sprint-2/1-key-errors/0.js

@@ -1,13 +1,22 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  =============> write your prediction here => This code will throw a syntax error
+// because the parameter str is redeclared as a let variable inside the function, which is not allowed.
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
 
+// function capitalise(str) {
+//   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
+//   return str;
+// }
+
+// =============> write your explanation here => The error occurs because we cannot declare
+// a new variable with the same name as a function parameter (str) using let inside the function.
+// This causes a "Identifier 'str' has already been declared" error according to mdn.
+
+// =============> write your new code here
 function capitalise(str) {
-  let str = `${str[0].toUpperCase()}${str.slice(1)}`;
-  return str;
+  return `${str[0].toUpperCase()}${str.slice(1)}`;
 }
 
-// =============> write your explanation here
-// =============> write your new code here
+console.log(capitalise("bethan"));

Sprint-2/1-key-errors/1.js

@@ -2,19 +2,32 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
+// An error will occur because 'decimalNumber' is redeclared inside the function using 'const',
+// which is not allowed. Also, 'decimalNumber' is not defined in the global scope,
+// so console.log(decimalNumber) will throw a ReferenceError.
 
 // Try playing computer with the example to work out what is going on
 
-function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
-  const percentage = `${decimalNumber * 100}%`;
+// function convertToPercentage(decimalNumber) {
+//   const decimalNumber = 0.5;
+//   const percentage = `${decimalNumber * 100}%`;
 
-  return percentage;
-}
+//   return percentage;
+// }
 
-console.log(decimalNumber);
+// console.log(decimalNumber);
 
 // =============> write your explanation here
+// The error occurs because we cannot redeclare the parameter 'decimalNumber' inside the function
+// using 'const'. Also, 'decimalNumber' is not defined outside the function, so
+// console.log(decimalNumber) will throw a ReferenceError.
 
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+
+function convertToPercentage(decimalNumber) {
+  const percentage = `${decimalNumber * 100}%`;
+  return percentage;
+}
+
+console.log(convertToPercentage(0.9)); // Output: 90%

Sprint-2/1-key-errors/2.js

@@ -1,20 +1,25 @@
-
 // Predict and explain first BEFORE you run any code...
 
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+// The code will throw a syntax error because you cannot use a number as a function parameter.
 
-function square(3) {
-    return num * num;
-}
+// function square(3) {
+//     return num * num;
+// }
 
 // =============> write the error message here
+// SyntaxError: Unexpected number
 
 // =============> explain this error message here
+// Function parameters must be variable names, not values. Using a number as a parameter is invalid syntax in JavaScript -mdn
 
 // Finally, correct the code to fix the problem
 
 // =============> write your new code here
+function square(num) {
+  return num * num;
+}
 
-
+console.log(square(7));

Sprint-2/2-mandatory-debug/0.js

@@ -1,14 +1,23 @@
-// Predict and explain first...
-
 // =============> write your prediction here
+// function multiply(a, b) {
+//   console.log(a * b);
+// }
 
-function multiply(a, b) {
-  console.log(a * b);
-}
+// console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
-console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
+// The output will be:
+// 320
+// The result of multiplying 10 and 32 is undefined
+// This is because multiply logs the result but does not return it, so the template literal gets undefined.
 
 // =============> write your explanation here
+// The function multiply only prints the result to the console and does not return anything.
+// When we use multiply(10, 32) inside the template literal, it evaluates to undefined because the function has no return value.
 
 // Finally, correct the code to fix the problem
 //  =============> write your new code here
+function multiply(a, b) {
+  return a * b;
+}
+
+console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);

Sprint-2/2-mandatory-debug/1.js

@@ -1,13 +1,21 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// function sum(a, b) {
+//   return;
+//   a + b;
+// }
 
-function sum(a, b) {
-  return;
-  a + b;
-}
-
-console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
+// console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
+// The output will be: The sum of 10 and 32 is undefined
+// This is because the function returns immediately with no value, so a + b is never executed.
 
 // =============> write your explanation here
+// The return statement ends the function before a + b is calculated, so the function returns undefined.
+
 // Finally, correct the code to fix the problem
 //  =============> write your new code here
+function sum(a, b) {
+  return a + b;
+}
+
+console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);

Sprint-2/2-mandatory-debug/2.js

@@ -2,23 +2,36 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+// The output will be:
+// The last digit of 42 is 3
+// The last digit of 105 is 3
+// The last digit of 806 is 3
+// Because getLastDigit always uses the global variable num (103) and ignores the argument.
 
-const num = 103;
+// const num = 103;
 
-function getLastDigit() {
-  return num.toString().slice(-1);
-}
+// function getLastDigit() {
+//   return num.toString().slice(-1);
+// }
 
-console.log(`The last digit of 42 is ${getLastDigit(42)}`);
-console.log(`The last digit of 105 is ${getLastDigit(105)}`);
-console.log(`The last digit of 806 is ${getLastDigit(806)}`);
+// console.log(`The last digit of 42 is ${getLastDigit(42)}`);
+// console.log(`The last digit of 105 is ${getLastDigit(105)}`);
+// console.log(`The last digit of 806 is ${getLastDigit(806)}`);
 
-// Now run the code and compare the output to your prediction
+// // Now run the code and compare the output to your prediction
 // =============> write the output here
 // Explain why the output is the way it is
 // =============> write your explanation here
+// The function getLastDigit does not accept any parameters and always uses the global variable num (103).
+// So, regardless of the argument passed, it always returns the last digit of 103, which is "3".
+
 // Finally, correct the code to fix the problem
 // =============> write your new code here
-
+function getLastDigit(num) {
+  return num.toString().slice(-1);
+}
+console.log(`The last digit of 42 is ${getLastDigit(42)}`);
+console.log(`The last digit of 105 is ${getLastDigit(105)}`);
+console.log(`The last digit of 806 is ${getLastDigit(806)}`);
 // This program should tell the user the last digit of each number.
 // Explain why getLastDigit is not working properly - correct the problem

Sprint-2/3-mandatory-implement/1-bmi.js

@@ -15,5 +15,10 @@
 // It should return their Body Mass Index to 1 decimal place
 
 function calculateBMI(weight, height) {
-    // return the BMI of someone based off their weight and height
-}
+  // Calculate BMI: weight divided by height squared
+  const bmi = weight / Math.pow(height, 2);
+  // Return BMI rounded to 1 decimal place
+  return +bmi.toFixed(1);
+}
+
+console.log(calculateBMI(78, 1.72));

Sprint-2/3-mandatory-implement/2-cases.js

@@ -14,3 +14,11 @@
 // You will need to come up with an appropriate name for the function
 // Use the MDN string documentation to help you find a solution
 // This might help https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toUpperCase
+
+function toUpperSnakeCase(str) {
+  // Replace spaces with underscores and convert to uppercase
+  return str.replace(/ /g, "_").toUpperCase();
+}
+
+console.log(toUpperSnakeCase("hello there")); // "HELLO_THERE"
+console.log(toUpperSnakeCase("lord of the rings")); // "LORD_OF_THE_RINGS"

Sprint-2/3-mandatory-implement/3-to-pounds.js

@@ -4,3 +4,21 @@
 // You will need to declare a function called toPounds with an appropriately named parameter.
 
 // You should call this function a number of times to check it works for different inputs
+
+function toPounds(penceString) {
+  // Remove trailing 'p' and pad with zeros to ensure at least 3 digits
+  const pence = penceString
+    .substring(0, penceString.length - 1)
+    .padStart(3, "0");
+  // Get pounds and pence parts
+  const pounds = pence.substring(0, pence.length - 2);
+  const pencePart = pence.substring(pence.length - 2).padEnd(2, "0");
+  // Return formatted string
+  return `£${pounds}.${pencePart}`;
+}
+
+console.log(toPounds("399p")); // £3.99
+console.log(toPounds("9p")); // £0.09
+console.log(toPounds("99p")); // £0.99
+console.log(toPounds("100p")); // £1.00
+console.log(toPounds("1234p")); // £12.34

Sprint-2/4-mandatory-interpret/time-format.js

@@ -18,17 +18,22 @@ function formatTimeDisplay(seconds) {
 
 // a) When formatTimeDisplay is called how many times will pad be called?
 // =============> write your answer here
+// pad will be called 3 times (once for hours, once for minutes, once for seconds).
 
 // Call formatTimeDisplay with an input of 61, now answer the following:
 
 // b) What is the value assigned to num when pad is called for the first time?
 // =============> write your answer here
+// The first call is pad(totalHours). For input 61, totalHours is 0.
 
 // c) What is the return value of pad is called for the first time?
 // =============> write your answer here
+// pad(0) returns "00".
 
 // d) What is the value assigned to num when pad is called for the last time in this program?  Explain your answer
 // =============> write your answer here
+// The last call is pad(remainingSeconds). For input 61, remainingSeconds is 1.
 
 // e) What is the return value assigned to num when pad is called for the last time in this program?  Explain your answer
 // =============> write your answer here
+// pad(1) returns "01".

Sprint-2/5-stretch-extend/format-time.js

@@ -2,24 +2,71 @@
 // Make sure to do the prep before you do the coursework
 // Your task is to write tests for as many different groups of input data or edge cases as you can, and fix any bugs you find.
 
+// function formatAs12HourClock(time) {
+//   const hours = Number(time.slice(0, 2));
+//   if (hours > 12) {
+//     return `${hours - 12}:00 pm`;
+//   }
+//   return `${time} am`;
+// }
+
+// const currentOutput = formatAs12HourClock("08:00");
+// const targetOutput = "08:00 am";
+// console.assert(
+//   currentOutput === targetOutput,
+//   `current output: ${currentOutput}, target output: ${targetOutput}`
+// );
+
+// const currentOutput2 = formatAs12HourClock("23:00");
+// const targetOutput2 = "11:00 pm";
+// console.assert(
+//   currentOutput2 === targetOutput2,
+//   `current output: ${currentOutput2}, target output: ${targetOutput2}`
+// );
+
 function formatAs12HourClock(time) {
   const hours = Number(time.slice(0, 2));
+  const minutes = time.slice(3, 5);
+
+  if (hours === 0) {
+    return `12:${minutes} am`;
+  }
+  if (hours === 12) {
+    return `12:${minutes} pm`;
+  }
   if (hours > 12) {
-    return `${hours - 12}:00 pm`;
+    return `${pad(hours - 12)}:${minutes} pm`;
   }
-  return `${time} am`;
+  return `${pad(hours)}:${minutes} am`;
+}
+
+function pad(num) {
+  return num.toString().padStart(2, "0");
 }
 
-const currentOutput = formatAs12HourClock("08:00");
-const targetOutput = "08:00 am";
+// Test cases for different groups of input data and edge cases
 console.assert(
-  currentOutput === targetOutput,
-  `current output: ${currentOutput}, target output: ${targetOutput}`
+  formatAs12HourClock("00:00") === "12:00 am",
+  "Test midnight failed"
 );
-
-const currentOutput2 = formatAs12HourClock("23:00");
-const targetOutput2 = "11:00 pm";
+console.assert(formatAs12HourClock("01:00") === "01:00 am", "Test 1am failed");
+console.assert(formatAs12HourClock("08:00") === "08:00 am", "Test 8am failed");
+console.assert(formatAs12HourClock("12:00") === "12:00 pm", "Test noon failed");
+console.assert(formatAs12HourClock("13:00") === "01:00 pm", "Test 1pm failed");
+console.assert(
+  formatAs12HourClock("11:59") === "11:59 am",
+  "Test 11:59am failed"
+);
+console.assert(
+  formatAs12HourClock("12:59") === "12:59 pm",
+  "Test 12:59pm failed"
+);
+console.assert(
+  formatAs12HourClock("15:30") === "03:30 pm",
+  "Test 3:30pm failed"
+);
+console.assert(formatAs12HourClock("23:00") === "11:00 pm", "Test 11pm failed");
 console.assert(
-  currentOutput2 === targetOutput2,
-  `current output: ${currentOutput2}, target output: ${targetOutput2}`
+  formatAs12HourClock("23:59") === "11:59 pm",
+  "Test 11:59pm failed"
 );

prep/example.js

@@ -0,0 +1,15 @@
+// function decimalTopercent(num){
+// 	let percent = num * 100;
+// 	return percent
+// }
+// console.log(decimalTopercent(0.5) + "%");
+
+function convertToPercentage(decimalNumber) {
+  const percentage = `${decimalNumber * 100}%`;
+  return percentage;
+}
+
+const result = convertToPercentage(0.5);
+const result1 = convertToPercentage(0.231);
+console.log(result);
+console.log(result1);