London | May 2025 | Halimatou Saddiyaa | Module-Structuring-and-Testing-Data | Sprint 2

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

@@ -1,6 +1,8 @@
 // Predict and explain first...
 //  =============> write your prediction here
 
+// I think the code will not rum properly because let in line 10 should be declared before the function in line 9 is called.
+
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
 
@@ -10,4 +12,14 @@ function capitalise(str) {
 }
 
 // =============> write your explanation here
+
+// The error is: Uncaught SyntaxError: Identifier 'str' has already been declared. It means that we cannot declare a variable with the same name as a parameter inside the function. In this case, We don't need the declaration let as str is already declared in the function's parameter.
+
 // =============> write your new code here
+
+function capitalise(str) {
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return str;
+}
+
+console.log(capitalise("hello world"));

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

@@ -3,6 +3,8 @@
 // Why will an error occur when this program runs?
 // =============> write your prediction here
 
+//I think an error will occur when this program runs because the variable decimalNumber is declared in line 10 in the parameter of the function and on line 11 as a constant.
+
 // Try playing computer with the example to work out what is going on
 
 function convertToPercentage(decimalNumber) {
@@ -16,5 +18,15 @@ console.log(decimalNumber);
 
 // =============> write your explanation here
 
+// The error is: Uncaught SyntaxError: Identifier 'decimalNumber' has already been declared. This means that we cannot declare a variable with the same name as a parameter inside the function. In this case, we don't need the declaration const as decimalNumber is already declared in the function's parameter.
+
 // 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

@@ -4,17 +4,27 @@
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+//The error will probably be related to the digit 3 in the function because 3 is not considered as a number in javascript. We need to explicitly declare it as a number for the code to run.
 
 function square(3) {
     return num * num;
 }
 
 // =============> write the error message here
+// The error message is: Uncaught SyntaxError: Unexpected number 
 
 // =============> explain this error message here
+//The error message means that we cannot use a digit number as a parameter name in a function. In this case, we need to use a valid variable name that Javascript recognises like num instead of the digit number 3.
 
 // 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

@@ -2,6 +2,8 @@
 
 // =============> write your prediction here
 
+// I think the error will probably be because the function is not followed by a return statement.
+
 function multiply(a, b) {
   console.log(a * b);
 }
@@ -10,5 +12,14 @@ console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // =============> write your explanation here
 
+// The message printed is "The result of multiplying 10 and 32 is undefined". As the function multiply does not have a return statement, console.log cannot print the result of the multiplication.
+// To allow the function to return the result of the multiplication, we need to add a return statement inside the function.
+
 // 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

@@ -1,6 +1,8 @@
 // Predict and explain first...
 //  =============> write your prediction here
 
+// I think the error will probably be because the return statement is not correctly placed in the function.
+
 function sum(a, b) {
   return;
   a + b;
@@ -9,5 +11,15 @@ function sum(a, b) {
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
+
+// The message printed is "The sum of 10 and 32 is undefined". As the expression of the return statement is placed in a new line, it is not being executed.
+// To allow the function to return the result of the sum, we need to place the expression in the same line as 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

@@ -3,6 +3,8 @@
 // Predict the output of the following code:
 // =============> Write your prediction here
 
+// I think the error will probably be because num as been defined as a constant with a value. So the function will only return the output with the constant num as a value.
+
 const num = 103;
 
 function getLastDigit() {
@@ -15,10 +17,27 @@ 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 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
+
+// The output is like this because  the function parameter is not being used. So, the function is using the constant num with a value of 103. That's why the last digit of each number is always 3, which is the last digit of 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

@@ -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
-}
+  // return the BMI of someone based off their weight and height
+
+  const bmi = weight / (height * height);
+  return 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 convertToUpperSnakeCase(input) {
+  return input.toUpperCase().replaceAll(" ", "_");
+}
+
+console.log(convertToUpperSnakeCase("hello there"));
+console.log(convertToUpperSnakeCase("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
+
+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)
+    .padEnd(2, "0");
+
+  return `£${pounds}.${pence}`;
+}
+
+console.log(toPounds("399p"));
+console.log(toPounds("8p"));
+console.log(toPounds("77p"));
+console.log(toPounds("1007p"));

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

@@ -11,24 +11,31 @@ function formatTimeDisplay(seconds) {
   return `${pad(totalHours)}:${pad(remainingMinutes)}:${pad(remainingSeconds)}`;
 }
 
+console.log(formatTimeDisplay(61));
+
 // 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
+// pad will be called 3 times, one for totalHours, one for remainingMinutes and one for remainingSeconds
 
 // 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
+// It is 0 because it is calling for totalHours which is 0 in this case.
 
 // c) What is the return value of pad is called for the first time?
 // =============> write your answer here
+// It is '00' because the function converts the number 0 to a string and pads it with zeros to make sure it is at least 2 characters long.
 
 // 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
+// It is 1 because it is calling for remainingSeconds which is 1 in this case.
 
 // 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
+// It is '01' because the function converts the number 1 to a string and pads it with zeros to make sure it is at least 2 characters long.