Glasgow | ITP May '25 | Mirabelle Morah | Module-Structuring-and-Testing-Data | Sprint 2

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

@@ -1,13 +1,24 @@
 // Predict and explain first...
 //  =============> write your prediction here
 
+/* 💡Answer: To be honest, I get confused when I see template literals and understand the older version of writing JS better, using operators, but I am dedicated to trying my best in this. I see a lot of the use of 'str' in this and I suspect this is almost correct but may fail because of the variable name 'str' used one too many times, as a parameter and a variable. I know that slice deletes parts of a string and 'toUpperCase' could be to capitalise things. */
+
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
 
-function capitalise(str) {
+/* function capitalise(str) {
   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
 }
+  */
+
+// =============> What I get is a "SyntaxError: Identifier 'str' has already been declared". This means that in line 10 of my code, I have declared the variable 'str' twice, once as a parameter and once as a variable. This is not allowed in JavaScript, as each variable must have a unique name within its scope. To fix this, I need to remove the 'let' keyword from the second declaration of 'str', so that I am simply reassigning the value to the existing parameter instead of trying to declare it again.
 
-// =============> write your explanation here
 // =============> write your new code here
+
+function capitalise(str) {
+  str = str[0].toUpperCase() + str.slice(1);
+  return str;
+}
+
+console.log(capitalise("wheew! Done it without template literals :)")); // Should print "Wheew! Done it without template literals :)"

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

@@ -1,10 +1,11 @@
 // Predict and explain first...
 
 // Why will an error occur when this program runs?
-// =============> write your prediction here
+// =============> 💡Answer: Same issue as in the firts one, you're redeclaring a parameter. What we can do is to assign the same parameter with new value.
 
 // Try playing computer with the example to work out what is going on
 
+/*
 function convertToPercentage(decimalNumber) {
   const decimalNumber = 0.5;
   const percentage = `${decimalNumber * 100}%`;
@@ -13,8 +14,17 @@ function convertToPercentage(decimalNumber) {
 }
 
 console.log(decimalNumber);
+*/
 
-// =============> write your explanation here
+// =============> it is giving me a "SyntaxError: Identifier 'decimalNumber' has already been declared" error. This is because I am trying to declare the variable 'decimalNumber' again inside the function, but it has already been declared as a parameter. In JavaScript, you cannot declare a variable with the same name in the same scope.
+// To fix this, I need to remove the 'const' keyword from the second declaration.
 
 // 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)); // Output: "50%"

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

@@ -1,20 +1,23 @@
-
 // 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
+// =============> 💡Answer: Mhmm there seems to be an error in line 8 because you can't use a number/integer alone as the start name of a parameter. It should be more of a name or string or add the number at the end of the value/name
 
-function square(3) {
+/* function square(3) {
     return num * num;
 }
+    */
 
-// =============> write the error message here
+// =============> write the error message here: "SyntaxError: Unexpected number" and "ReferenceError: num is not defined"
 
-// =============> explain this error message here
+// =============> explain this error message here: Using a number alone is not a valid identifier name in JavaScript. Identifiers must start with a letter, underscore (_), or dollar sign ($). Also , the variable `num` is not defined anywhere in the function, which leads to a ReferenceError when trying to use it.
 
 // Finally, correct the code to fix the problem
 
-// =============> write your new code here
-
+// =============>
+function square(Now3) {
+  return Now3 * Now3;
+}
 
+console.log(square(3)); // Output: 9

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

@@ -1,14 +1,22 @@
 // Predict and explain first...
 
-// =============> write your prediction here
+// =============> Answer 💡: does not have a return statement, so it will return undefined
 
-function multiply(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)}`); */
 
-// =============> write your explanation here
+// =============> write your explanation here: The code shows the message
+// "320 The result of multiplying 10 and 32 is undefined"
+// It is because the multiply function does not return a value, it only logs the result to the console.
 
 // 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)}`); // logs "The result of multiplying 10 and 32 is 320"

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

@@ -1,13 +1,20 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  =============> write your prediction here: Answer 💡: looks like it will fail because of the way return is written
 
-function sum(a, b) {
+/*function sum(a, b) {
   return;
   a + b;
 }
 
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
+*/
 
-// =============> write your explanation here
+// =============> write your explanation here: The error occurs because the return statement is used incorrectly. It has a semicolon after it, which causes the function to return undefined immediately, and the line `a + b;` is never executed.
 // 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)}`); // logs "The sum of 10 and 32 is 42"

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

@@ -1,24 +1,40 @@
 // Predict and explain first...
 
 // Predict the output of the following code:
-// =============> Write your prediction here
+// =============> Write your prediction here --  Answer 💡: no parameter for function getLastDigit()
 
-const num = 103;
+/*const num = 103;
 
 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 806 is ${getLastDigit(806)}`); */
 
 // Now run the code and compare the output to your prediction
 // =============> write the output here
+//
+/* -- because there's no parameter, the console logs teh following for all the function calls
+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
+// =============> This is as a result of the function always using the constant variable num, outside the function, which is set to 103, to get its answer.
 // Finally, correct the code to fix the problem
 // =============> write your new code here
 
 // This program should tell the user the last digit of each number.
 // Explain why getLastDigit is not working properly - correct the problem
+
+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)}`);
+
+// The function now takes a parameter 'number' and uses it to get the last digit of the number passed to it. This is because .slice(-1) is used to get the last character of the string representation of the number.

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

@@ -15,5 +15,9 @@
 // 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); // rounds to 1 decimal place & returns a string
+}
+
+console.log(`The BMI is ${calculateBMI(70, 1.51)}`); // logs "The BMI is 30.7"

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

@@ -14,3 +14,9 @@
 // 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("what a lovely day")); // Output: "WHAT_A_LOVELY_DAY"

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")); // Output: £3.99
+console.log(toPounds("99p")); // Output: £0.99
+console.log(toPounds("1p")); // Output: £0.01

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

@@ -11,24 +11,26 @@ function formatTimeDisplay(seconds) {
   return `${pad(totalHours)}:${pad(remainingMinutes)}:${pad(remainingSeconds)}`;
 }
 
+console.log(formatTimeDisplay(61)); // Output: 00:01:01
+
 // 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
+// =============> the answer is 0 (that is 00:01:01)
 
 // 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
 
 // 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, because it adds a zero at the front to keep it within the HH:MM:SS format (that is 00:01:01)