Manchester | 25-ITP-May | Jennifer Isidienu | Sprint 2 | Acoursework

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

@@ -1,5 +1,6 @@
 // Predict and explain first...
-//  =============> write your prediction here
+// =============> write your prediction here
+// The code below is expected to show an error because the variable 'str' is declared twice.
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
@@ -10,4 +11,11 @@ function capitalise(str) {
 }
 
 // =============> write your explanation here
+// The error occurs because the variable 'str' is declared with 'let' twice in the same scope.
+// The first declaration is a placeholder value, and the second is a variable declaration inside the function.
 // =============> write your new code here
+// To fix this, we can remove the 'let' keyword from the second declaration of 'str'.
+function capitalise(str) {
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return str;
+}

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

@@ -2,9 +2,10 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
+// An error will occur because the variable `decimalNumber` is declared twice, 
+// which is not allowed in JavaScript.
 
 // Try playing computer with the example to work out what is going on
-
 function convertToPercentage(decimalNumber) {
   const decimalNumber = 0.5;
   const percentage = `${decimalNumber * 100}%`;
@@ -15,6 +16,18 @@ function convertToPercentage(decimalNumber) {
 console.log(decimalNumber);
 
 // =============> write your explanation here
+// The error occurs because the variable 'decimalNumber' is declared again 
+// inside the function 'convertToPercentage', although it has already been 
+// defined as a parameter. JavaScript does not allow redeclaring a parameter 
+// using const, let or var within the same scope. This causes a syntax error 
+// when the code is executed.
 
 // 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(0.5));

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

@@ -1,20 +1,34 @@
 
 // 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
+// It will show an error because function parameters must be variable names,
+// not literal values.
 
-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
+// The error message "SyntaxError: Unexpected number" indicates that 
+// the JavaScript interpreter encountered a number instead of a valid 
+// identifier like a variable name.
+// In function declarations, parameters must be variable names and not 
+// literal values like 3. That is why using function square(3) caused a syntax error.
 
 // Finally, correct the code to fix the problem
 
 // =============> write your new code here
 
+function square(num) {
+  return num * num;
+}
+
+console.log(square(3)); 
 

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

@@ -1,6 +1,8 @@
 // Predict and explain first...
 
 // =============> write your prediction here
+//The code will be undefined because the "console.log(a * b)" function
+// will not return a value, rather it will only log a result.
 
 function multiply(a, b) {
   console.log(a * b);
@@ -9,6 +11,17 @@ function multiply(a, b) {
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // =============> write your explanation here
+// The `multiply` function is designed to log the product of `a` and `b` 
+// to the console, but it does not return any value.
+// When `multiply(10, 32)` is used inside the template string, 
+// it shows `undefined` because the function does not return anything.
+// As a result, the console will first display 320 from inside the function,
+// and then print; "The result of multiplying 10 and 32 is undefined".
 
 // 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

@@ -9,5 +9,15 @@ function sum(a, b) {
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
+/// The code is expected to return undefined because the return statement 
+// is placed before the actual addition operation. The function `sum` is 
+// defined to take two parameters, `a` and `b`, but it does not return their 
+// sum due to the misplaced semicolon after the `return` statement.
+
 // 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

@@ -15,10 +15,28 @@ console.log(`The last digit of 806 is ${getLastDigit(806)}`);
 
 // Now run the code and compare the output to your prediction
 // =============> write the output here
+// The last digit of 42 is 3
+// The last digit of 105 is 3
+// The last digit of 806 is 3
+
 // Explain why the output is the way it is
 // =============> write your explanation here
+// The function `getLastDigit` does not accept any arguments. 
+// It always uses the constant `num` defined at the top, which is 103. 
+// Therefore, no matter what number is passed in the `console.log`, 
+// the function always returns the last digit of 103 ("3").
+// `getLastDigit` passes a value that is ignored since the function 
+// takes no parameters and always uses the fixed variable num = 103.
+
 // 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

@@ -1,19 +1,26 @@
 // Below are the steps for how BMI is calculated
 
-// The BMI calculation divides an adult's weight in kilograms (kg) by their height in metres (m) squared.
+// The BMI calculation divides an adult's weight in kilograms (kg) 
+// by their height in metres (m) squared.
 
-// For example, if you weigh 70kg (around 11 stone) and are 1.73m (around 5 feet 8 inches) tall, you work out your BMI by:
+// For example, if you weigh 70kg (around 11 stone) and are 1.73m 
+// (around 5 feet 8 inches) tall, you work out your BMI by:
 
 // squaring your height: 1.73 x 1.73 = 2.99
 // dividing 70 by 2.99 = 23.41
 // Your result will be displayed to 1 decimal place, for example 23.4.
 
-// You will need to implement a function that calculates the BMI of someone based off their weight and height
+// You will need to implement a function that calculates the BMI of someone
+// based off their weight and height
 
 // Given someone's weight in kg and height in metres
 // Then when we call this function with the weight and height
 // 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
-}
+// return the BMI of someone based off their weight and height
+    const BMI = weight / (height * height);
+    return Number(BMI.toFixed(1)); 
+}
+
+console.log(calculateBMI(70, 1.73)); 

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

@@ -14,3 +14,10 @@
 // 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(input) {
+  return input.toUpperCase().replaceAll(" ", "_");
+}
+
+console.log(toUpperSnakeCase("hello there"));
+console.log(toUpperSnakeCase("lord of the rings"));

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

@@ -4,3 +4,27 @@
 // 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
+
+// This function converts a string like "399p" into a formatted pounds and pence amount like "£3.99"
+
+function toPounds(penceString) {
+
+  const penceStringWithoutTrailingP = penceString
+  .substring(0, penceString.length - 1);
+
+  const paddedPenceNumberString = 
+  penceStringWithoutTrailingP.padStart(3, "0");
+
+  const pounds = paddedPenceNumberString
+  .substring(0, paddedPenceNumberString.length - 2);
+
+  const pence = paddedPenceNumberString
+    .substring(paddedPenceNumberString.length - 2);
+
+  return `£${pounds}.${pence}`;
+}
+console.log(toPounds("399p"));  
+console.log(toPounds("99p"));  
+console.log(toPounds("5p"));  
+console.log(toPounds("1399p"));  
+console.log(toPounds("0p"));  

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

@@ -11,24 +11,45 @@ function formatTimeDisplay(seconds) {
   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
+// 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?
+// a) When formatTimeDisplay is called how many 
+// times will pad be called?
 // =============> write your answer here
+// 3 times. It is called once for hours, 
+// once for minutes and 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?
+// b) What is the value assigned to num when 
+// pad is called for the first time?
 // =============> write your answer here
+//  The value assigned to num when pad is 
+// called for the first time is 0.
 
 // c) What is the return value of pad is called for the first time?
 // =============> write your answer here
+// The return value of pad when called for the first time is "00". 
+// This is because it pads the number 0 with leading zeros to 
+// ensure it has a length of 2 characters.
 
-// d) What is the value assigned to num when pad is called for the last time in this program?  Explain your answer
+// 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 value assigned to num when pad is called for the last time is 1.
+// This is because the last call to pad is for the remaining seconds
+// which is 61 % 60 = 1.
 
-// e) What is the return value assigned to num when pad is called for the last time in this program?  Explain your answer
+// 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
+// The return value assigned to num when pad is called for 
+// the last time is "01".
+// This is because it applies .padStart(2, "0"), which returns 
+// a two character string, with a leading zero to ensure 
+// it has a minimum length of 2.

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

@@ -1,6 +1,8 @@
 // This is the latest solution to the problem from the prep.
 // 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.
+// 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));
@@ -23,3 +25,27 @@ console.assert(
   currentOutput2 === targetOutput2,
   `current output: ${currentOutput2}, target output: ${targetOutput2}`
 );
+
+//
+function formatAs12HourClock(time) {
+  const [hourStr, minutes] = time.split(":");
+  const hours = Number(hourStr);
+
+  if (hours === 0) {
+    return `12:${minutes} am`;  // Midnight 
+  }
+  if (hours === 12) {
+    return `12:${minutes} pm`;  // Noon 
+  }
+  if (hours > 12) {
+    return `${String(hours - 12).padStart(2, "0")}:${minutes} pm`;  
+  }
+  return `${time} am`;  // Morning
+}
+
+// Test cases
+console.log(formatAs12HourClock("08:00"));  
+console.log(formatAs12HourClock("23:00"));  
+console.log(formatAs12HourClock("00:30"));  
+console.log(formatAs12HourClock("12:45"));  
+console.log(formatAs12HourClock("13:15"));