Barcelona | Oct2025-2 | Roman Pavlenko | Sprint-2 | Coursework

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

@@ -1,13 +1,26 @@
 // Predict and explain first...
 //  =============> write your prediction here
 
+// this let statement is trying to declare a variable with the same name as the function parameter 'str',
+// which will cause a syntax error because you cannot redeclare a parameter within the same scope.
+
 // call the function capitalise with a string input
+
+// we don't call the function here, but if we did, it would result in an error due to the redeclaration of 'str'.
 // 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;
-}
+// function capitalise(str) {
+//   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
+//   return str;
+// }
 
 // =============> write your explanation here
 // =============> write your new code here
+
+
+function capitalise(str) {
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return str;
+}
+console.log(capitalise('hello'));
+// Hello 

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

@@ -1,20 +1,31 @@
 // Predict and explain first...
 
 // Why will an error occur when this program runs?
+// SyntaxError: Identifier 'decimalNumber' has already been declared
+// We don't need to redeclare the variable decimalNumber inside the function because it's already declared as a
+// parameter. This causes a conflict in the scope of the function.
 // =============> write your prediction here
 
 // 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
 
 // 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(0.75)); // 75%
+console.log(convertToPercentage(0.2));  // 20%
+console.log(convertToPercentage(0.5));  // 50%

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

@@ -1,15 +1,21 @@
 
 // Predict and explain first BEFORE you run any code...
-
+// We neet to call the function square with a number argument, and change the parameter name to a num here.
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
 
-function square(3) {
+function square(num) {  // changed parameter name from 3 to num
     return num * num;
 }
+console.log(square(4)); // 16
+console.log(square(10));
 
 // =============> write the error message here
+// function square(3) {
+//                 ^
+
+// SyntaxError: Unexpected number
 
 // =============> explain this error message here
 

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

@@ -1,9 +1,10 @@
 // Predict and explain first...
 
 // =============> write your prediction here
-
+// We're going to get 320 and 'The result of multiplying 10 and 32 is undefined' 
+// because the multiply function does not return a value; it only logs the product to the console.
 function multiply(a, b) {
-  console.log(a * b);
+  return (a * b);
 }
 
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
@@ -12,3 +13,4 @@ console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // Finally, correct the code to fix the problem
 //  =============> write your new code here
+// we have to replace console.log with return in the multiply function

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

@@ -1,13 +1,14 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// We're going to get undefined because the sum function has a return statement that does not return any value.
 
 function sum(a, b) {
-  return;
-  a + b;
+  return a + b;
 }
 
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
 // Finally, correct the code to fix the problem
 //  =============> write your new code here
+// we just remove the semicolon after return statement and return the sum of a and b

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

@@ -2,11 +2,16 @@
 
 // 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 the function getLastDigit always returns the last digit of the constant variable num which is set to 103.
 const num = 103;
 
-function getLastDigit() {
-  return num.toString().slice(-1);
+function getLastDigit(a) {
+  return a.toString().slice(-1);
+
 }
 
 console.log(`The last digit of 42 is ${getLastDigit(42)}`);
@@ -19,6 +24,7 @@ console.log(`The last digit of 806 is ${getLastDigit(806)}`);
 // =============> write your explanation here
 // Finally, correct the code to fix the problem
 // =============> write your new code here
-
+// now it's working properly because we are returning the last digit of the argument a passed to the function getLastDigit 
+// instead of the constant variable num.
 // 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 +15,11 @@
 // It should return their Body Mass Index to 1 decimal place
 
 function calculateBMI(weight, height) {
+    const bmi = weight / (height * height);
+    return parseFloat(bmi.toFixed(1));
     // return the BMI of someone based off their weight and height
-}
+}
+const yourBMI = calculateBMI(70, 1.73);
+console.log(`Your BMI is ${yourBMI}`); // Your BMI is 23.4
+const anotherBMI = calculateBMI(95, 1.88);
+console.log(`Another person's BMI is ${anotherBMI}`); // Another person's BMI is 26.8

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

@@ -14,3 +14,12 @@
 // 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) {
+    return str.toUpperCase().replace(/ /g, '_');
+
+}
+
+console.log(toUpperSnakeCase('hello there')); // "HELLO_THERE"
+console.log(toUpperSnakeCase('lord of the rings')); // "LORD_OF_THE_RINGS"
+console.log(toUpperSnakeCase('JavaScript is fun')); // "JAVASCRIPT_IS_FUN"

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

@@ -4,3 +4,22 @@
 // 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) {
+    // return the amount in pounds and pence format
+    const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1);
+    // Ensure at least 3 digits for correct slicing
+    const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+    // Split into pounds and pence
+    const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2);
+    // Get last two digits for pence
+    const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"); 
+
+    return `£${pounds}.${pence}`;
+    }
+
+console.log(toPounds("399p")); // £3.99
+console.log(toPounds("50p")); // £0.50
+console.log(toPounds("5p")); // £0.05
+console.log(toPounds("1234p")); // £12.34

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

@@ -1,34 +1,43 @@
-function pad(num) {
-  return num.toString().padStart(2, "0");
-}
-
-function formatTimeDisplay(seconds) {
-  const remainingSeconds = seconds % 60;
-  const totalMinutes = (seconds - remainingSeconds) / 60;
-  const remainingMinutes = totalMinutes % 60;
-  const totalHours = (totalMinutes - remainingMinutes) / 60;
-
-  return `${pad(totalHours)}:${pad(remainingMinutes)}:${pad(remainingSeconds)}`;
-}
-
-// You will need to play computer with this example - use the Python Visualiser https://pythontutor.com/visualize.html#mode=edit
-// to help you answer these questions
-
-// Questions
-
-// a) When formatTimeDisplay is called how many times will pad be called?
-// =============> write your answer here
-
-// Call formatTimeDisplay with an input of 61, now answer the following:
-
-// b) What is the value assigned to num when pad is called for the first time?
-// =============> write your answer here
-
-// c) What is the return value of pad is called for the first time?
-// =============> write your answer here
-
-// d) What is the value assigned to num when pad is called for the last time in this program?  Explain your answer
-// =============> write your answer here
-
-// e) What is the return value assigned to num when pad is called for the last time in this program?  Explain your answer
-// =============> write your answer here
+function pad(num) {
+  return num.toString().padStart(2, "0");
+}
+
+function formatTimeDisplay(seconds) {
+  const remainingSeconds = seconds % 60;
+  const totalMinutes = (seconds - remainingSeconds) / 60;
+  const remainingMinutes = totalMinutes % 60;
+  const totalHours = (totalMinutes - remainingMinutes) / 60;
+  console.log(totalHours);
+
+  return `${pad(totalHours)}:${pad(remainingMinutes)}:${pad(remainingSeconds)}`;
+}
+console.log(formatTimeDisplay(12345)); 
+
+// You will need to play computer with this example - use the Python Visualiser https://pythontutor.com/visualize.html#mode=edit
+// to help you answer these questions
+
+// Questions
+
+// a) When formatTimeDisplay is called how many times will pad be called?
+// =============> write your answer here
+// 3 times
+
+
+// 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
+// 0 (when calculating hours) 
+
+// c) What is the return value of pad is called for the first time?
+// =============> write your answer here
+// "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
+// 1 (when calculating seconds)
+
+
+// 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
+// "01" (when calculating seconds)

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

@@ -0,0 +1,23 @@
+function formatAs12HourClock(time) {
+    const [hoursStr, minutes] = time.split(":");
+    const hours = parseInt(hoursStr, 10);
+    if (hours > 24 || minutes >= 60) {
+        throw new Error("Invalid time format");
+    }
+    if (hours >= 12) {
+        const adjustedHours = hours > 12 ? hours - 12 : hours;
+        return `${adjustedHours}:${minutes} pm`;
+    } else {
+        return `${hours}:${minutes} am`;
+    }
+}
+
+const moment = "13:45";
+console.log(formatAs12HourClock(moment)); // Output: 2:00 pm
+// console.log(formatAs12HourClock("00:30")); // "12:30 am"
+
+// const currentOutput = formatAs12HourClock("08:00");
+// const targetOutput = "08:00 am";
+// console.assert(
+//   currentOutput === targetOutput,
+//   `current output: ${currentOutput}, target output: ${targetOutput}`);

Sprint-2/codewars/Create Phone Number.js

@@ -0,0 +1,16 @@
+function createPhoneNumber(numbers) {
+  const area = numbers.slice(0, 3).join('');
+  const middle = numbers.slice(3, 6).join('');
+  const last = numbers.slice(6).join('');
+
+  return `(${area}) ${middle}-${last}`;
+}
+
+
+console.assert(createPhoneNumber([1, 2, 3, 4, 5, 6, 7, 8, 9, 0]) === '(123) 456-7890', 'Test Case 1 Failed');
+console.assert(createPhoneNumber([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]) === '(012) 345-6789', 'Test Case 2 Failed');
+
+
+
+console.log(createPhoneNumber([1, 2, 3, 4, 5, 6, 7, 8, 9, 0])); // Output: (123) 456-7890
+console.log(createPhoneNumber([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])); // Output: (012) 345-6789

Sprint-2/codewars/Fun with ES6 Classes

@@ -0,0 +1,34 @@
+class Human  {
+  firstName: string;
+  lastName: string;
+  age: number;
+  gender: string;
+
+  constructor(
+    firstName: string = "John",
+    lastName: string = "Doe",
+    age: number = 0,
+    gender: string = "Male"
+  ) {
+    this.firstName = firstName;
+    this.lastName = lastName;
+    this.age = age;
+    this.gender = gender;
+  }
+
+  sayFullName(): string {
+    return `${this.firstName} ${this.lastName}`;
+  }
+
+  static greetExtraTerrestrials(raceName: string): string {
+    return `Welcome to Planet Earth ${raceName}`;
+  }
+}
+
+// Example usage
+const roman = new Person("Roman", "Pavlenko", 36, "Male");
+console.log(roman.sayFullName()); 
+// Output: Roman Pavlenko
+
+console.log(Person.greetExtraTerrestrials("Martians"));
+// Output: Welcome to Planet Earth Martians

Sprint-2/codewars/Fun with ES6 Classes.js

@@ -0,0 +1,15 @@
+class Person {
+  constructor(firstName = 'John', lastName = 'Doe', age = 0, gender = 'Male') {
+    Object.assign(this, { firstName, lastName, age, gender });
+  }
+  sayFullName() {
+    return `${this.firstName} ${this.lastName}`;
+  }
+  static greetExtraTerrestrials(raceName) {
+    return `Welcome to Planet Earth ${raceName}`;
+  }
+}
+const person1 = new Person('Roman', 'Pavlenko', 36, 'Male');
+console.log(person1.sayFullName()); // Output: Jane Doe
+
+console.log(Person.greetExtraTerrestrials('Martians')); // Output: Welcome to Planet Earth Martians