Birmingham | 25-ITP-Sept | Khor Biel | Sprint 2 | courwork/sprint-2

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

@@ -1,5 +1,5 @@
 // Predict and explain first...
-//  =============> write your prediction here
+// I predict this code will cause a SyntaxError because of variable redeclaration.
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
@@ -9,5 +9,20 @@ function capitalise(str) {
   return str;
 }
 
-// =============> write your explanation here
-// =============> write your new code here
+// My explanation; The error occurs because:
+
+// str is declared as a function parameter
+// Inside the function, we try to declare another variable with let str = ...
+// This creates a naming conflict - you can't have two variables with the same name in the same scope when one is declared with let/const
+
+
+
+
+// My code:
+
+function capitalise(str) {
+  let result = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return result;
+}
+
+// This solution uses a different variable name (result) to store the capitalized string, avoiding the naming conflict while keeping the same logic.

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

@@ -1,7 +1,8 @@
 // Predict and explain first...
 
+
 // Why will an error occur when this program runs?
-// =============> write your prediction here
+// I predict this code will cause a SyntaxError because of constant redeclaration, and even if that were fixed, it would cause a ReferenceError when trying to access decimalNumber outside the function
 
 // Try playing computer with the example to work out what is going on
 
@@ -16,5 +17,23 @@ console.log(decimalNumber);
 
 // =============> write your explanation here
 
+// My explanation; There are two main problems:
+// SyntaxError: The parameter decimalNumber and the constant const decimalNumber = 0.5; have the same name in the same scope, causing a redeclaration error.
+// ReferenceError: Even if we fix the first issue, console.log(decimalNumber) tries to access a variable that only exists inside the function scope, not in the global scope.
+
+
+
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+
+// My code:
+
+function convertToPercentage(decimalNumber) {
+  const percentage = `${decimalNumber * 100}%`;
+  return percentage;
+}
+
+console.log(convertToPercentage(0.5));
+
+// I removed the redundant redeclaration of decimalNumber inside the function
+// I Changed console.log(decimalNumber) to actually call the function with convertToPercentage(0.5)

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

@@ -3,18 +3,29 @@
 
 // this function should square any number but instead we're going to get an error
 
-// =============> write your prediction of the error here
+// My predict is this code will cause a SyntaxError because of an invalid function parameter.
 
 function square(3) {
     return num * num;
 }
 
 // =============> write the error message here
+// SyntaxError: Unexpected number
 
-// =============> explain this error message here
+// My explanation;
+
+// The error occurs because:
+// Function parameters must be variable names (identifiers), not literal values
+// 3 is a number literal, not a valid parameter name
+// The function is trying to use num in the calculation, but num was never declared as a parameter
 
 // Finally, correct the code to fix the problem
 
-// =============> write your new code here
+// My new code:
 
+function square(num) {
+    return num * num;
+}
 
+// I replaced the invalid parameter 3 with a valid parameter name num
+// This allows the function to accept a number input and correctly calculate its square

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

@@ -1,14 +1,37 @@
 // Predict and explain first...
 
-// =============> write your prediction here
+// I predict that the output will be:
+// 320
+// The result of multiplying 10 and 32 is undefined
+
+
 
 function multiply(a, b) {
   console.log(a * b);
 }
 
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
-// =============> write your explanation here
+// My explanation; The issue is that:
+
+// The multiply function uses console.log(a * b) which prints 320 to the console
+// But the function doesn't return any value, so it implicitly returns undefined
+// When we try to interpolate ${multiply(10, 32)} in the template literal, it becomes undefined
+// So we get the unexpected output showing "The result... is undefined"
 
 // Finally, correct the code to fix the problem
-//  =============> write your new code here
+// My new code:
+
+function multiply(a, b) {
+  return a * b;
+}
+
+console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
+
+// Now the output will be:
+// The result of multiplying 10 and 32 is 320
+
+// The fix:
+
+// I Changed console.log(a * b) to return a * b so the function actually returns the result
+// The template literal can now properly display the calculated value

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

@@ -1,5 +1,6 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  I predict that the output will be:
+// The sum of 10 and 32 is undefined
 
 function sum(a, b) {
   return;
@@ -8,6 +9,29 @@ function sum(a, b) {
 
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
-// =============> write your explanation here
+// My explanation; The issue is with the semicolon after return:
+
+// When JavaScript sees return; with a semicolon, it immediately exits the function
+// The line a + b; is never executed because it comes after the return statement
+// Since return; doesn't return any value, the function returns undefined
+// Therefore, the template literal shows "The sum of 10 and 32 is undefined"
+// This is an example of automatic semicolon insertion causing unexpected behavior.
+
+
 // Finally, correct the code to fix the problem
-//  =============> write your new code here
+// My new code:
+
+
+function sum(a, b) {
+  return a + b;
+}
+
+console.log(`The sum of 10 and 32 is ${sum(10, 32)}`); 
+
+// Now the output will be:
+// The sum of 10 and 32 is 42
+
+// The fix:
+
+// I removed the semicolon after return so the expression a + b is properly returned
+// The function now correctly calculates and returns the sum

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

@@ -1,7 +1,10 @@
 // Predict and explain first...
 
 // Predict the output of the following code:
-// =============> Write your prediction here
+// I predict that 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
 
 const num = 103;
 
@@ -14,11 +17,44 @@ 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
-// =============> write the output here
+
+// After running the code, the actual output is:
+// 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
+
+// My explanation:
+// The problem is that the getLastDigit function ignores its parameter and always uses the global constant num which is set to 103:
+// The function takes a parameter but doesn't use it
+// Instead, it uses the global num variable (value: 103)
+// 103.toString().slice(-1) always returns "3"
+// So regardless of what number we pass to the function, it always returns "3"
+
+
+
+
 // Finally, correct the code to fix the problem
-// =============> write your new code here
+// My new code:
+
+function getLastDigit(number) {
+  return number.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
+
+
+// The output will now be:
+// The last digit of 42 is 2
+// The last digit of 105 is 5
+// The last digit of 806 is 6
+
+// The fix:
+// I changed the function to use its parameter (number) instead of the global (num) variable
+// The function now correctly returns the last digit of the number passed to it

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

@@ -16,4 +16,33 @@
 
 function calculateBMI(weight, height) {
     // return the BMI of someone based off their weight and height
-}
+}
+
+// Here's my implementation of the BMI calculation function, according to the steps provided and my understanding:
+
+function calculateBMI(weight, height) {
+    // Calculate height squared
+    const heightSquared = height * height;
+
+    // Calculate BMI (weight divided by height squared)
+    const bmi = weight / heightSquared;
+
+    // Return BMI rounded to 1 decimal place
+    return bmi.toFixed(1);
+}
+
+// Test with my values: weight = 70kg, height = 1.90m
+const weight = 70;
+const height = 1.90;
+const bmiResult = calculateBMI(weight, height);
+
+console.log(`For weight ${weight}kg and height ${height}m, the BMI is ${bmiResult}`);
+
+// Calculation breakdown for your values:
+
+// Height squared: 1.90 × 1.90 = 3.61
+// BMI: 70 ÷ 3.61 = 19.39...
+// Rounded to 1 decimal place: 19.4
+// So the function will return "19.4" for weight = 70kg and height = 1.90m.
+// The toFixed(1) method ensures the result is formatted to 1 decimal place as specified in the requirements.
+

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

@@ -14,3 +14,23 @@
 // 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
+
+
+// Here's my implementation of the function to convert a string to UPPER_SNAKE_CASE:
+
+function toUpperSnakeCase(inputString) {
+    // Replace spaces with underscores and convert to uppercase
+    return inputString.replace(/ /g, '_').toUpperCase();
+}
+
+// Test cases
+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"
+
+
+// How it works:
+
+// inputString.replace(/ /g, '_') - replaces all spaces with underscores
+// The / /g is a regular expression that matches all spaces globally
+// .toUpperCase() - converts the entire string to uppercase

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
+
+
+
+// Here's my implementation of the toPounds function:
+
+function toPounds(kilograms) {
+    const conversionRate = 2.20462;
+    const pounds = kilograms * conversionRate;
+    return pounds;
+}
+
+
+// The `toPounds` function works in 3 simple steps:
+
+// Takes input - the `kilograms` parameter receives a weight in kilograms
+// Converts - multiplies kilograms by 2.20462 (the conversion rate to pounds)
+// Returns result - gives back the calculated weight in pounds
+
+// Example: `toPounds(10)` calculates `10 × 2.20462 = 22.0462` and returns this value.

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

@@ -17,18 +17,27 @@ function formatTimeDisplay(seconds) {
 // Questions
 
 // a) When formatTimeDisplay is called how many times will pad be called?
-// =============> write your answer here
+// My answer: 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
+// My answer: 0 (totalHours = 0)
 
 // c) What is the return value of pad is called for the first time?
-// =============> write your answer here
+// My answer: "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
+// My answer: 1 (remainingSeconds = 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
-// =============> write your answer here
+// My answer: "01" (pad adds a leading zero to make it 2 digits)
+
+
+// Explanation for input 61:
+
+// totalHours = 0
+// remainingMinutes = 1
+// remainingSeconds = 1
+// pad is called 3 times: pad(0), pad(1), pad(1)
+// Returns "00:01:01"