Glasgow | 26-ITP-May | Francesco Romano Monda | Sprint 1 | Complete Sprint 1 Coursework

Sprint-1/1-key-exercises/1-count.js

@@ -4,3 +4,5 @@ count = count + 1;
 
 // Line 1 is a variable declaration, creating the count variable with an initial value of 0
 // Describe what line 3 is doing, in particular focus on what = is doing
+// Line 3 updates the variable count by taking its current value, adding 1 to it, and then assigning the new value back to count
+// The = sign assigns the value on the right to the variable on the left

Sprint-1/1-key-exercises/2-initials.js

@@ -5,7 +5,6 @@ let lastName = "Johnson";
 // Declare a variable called initials that stores the first character of each string.
 // This should produce the string "CKJ", but you must not write the characters C, K, or J in the code of your solution.
 
-let initials = ``;
+let initials = firstName.charAt(0) + middleName.charAt(0) + lastName.charAt(0);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
-

Sprint-1/1-key-exercises/3-paths.js

@@ -17,7 +17,8 @@ console.log(`The base part of ${filePath} is ${base}`);
 // Create a variable to store the dir part of the filePath variable
 // Create a variable to store the ext part of the variable
 
-const dir = ;
-const ext = ;
+const dir = filePath.slice(0, lastSlashIndex);
+const lastDotIndex = filePath.lastIndexOf(".");
+const ext = filePath.slice(lastDotIndex);
 
-// https://www.google.com/search?q=slice+mdn
+// https://www.google.com/search?q=slice+mdn

Sprint-1/1-key-exercises/4-random.js

@@ -3,7 +3,12 @@ const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 
-// In this exercise, you will need to work out what num represents?
+// In this exercise, you will need to work out what num represents
 // Try breaking down the expression and using documentation to explain what it means
 // It will help to think about the order in which expressions are evaluated
 // Try logging the value of num and running the program several times to build an idea of what the program is doing
+
+// Math.random() gives a random decimal number between 0 and 1
+// Math.random() * (maximum - minimum + 1) gives a random decimal number between 0 and 100
+// Math.floor() removes the decimal part, giving a whole number between 0 and 99
+// + minimum shifts the range up so the final result is between 1 and 100

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

@@ -1,2 +1,10 @@
 This is just an instruction for the first activity - but it is just for human consumption
-We don't want the computer to run these 2 lines - how can we solve this problem?
+We don't want the computer to run these 2 lines - how can we solve this problem?
+
+//The error message displayed by Node.js is:
+//Uncaught SyntaxError: Unexpected identifier 'is'
+//This is a syntax error. It occurs because JavaScript is trying to interpret an
+//English sentence as JavaScript code. After reading the word 'This', the JavaScript
+//parser expects a valid JavaScript operator. Instead, it encounters another variable
+//name, 'is', which is not valid in that position according to JavaScript's syntax rules.
+//As a result, the parser throws the error Unexpected identifier 'is'.

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

@@ -2,3 +2,7 @@
 
 const age = 33;
 age = age + 1;
+
+//The error message displayed by Node.js is:
+//Uncaught TypeError: Assignment to constant variable
+//The error happens because const creates a variable whose value cannot be reassigned.

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

@@ -1,5 +1,9 @@
 // Currently trying to print the string "I was born in Bolton" but it isn't working...
-// what's the error ?
+// what's the error?
 
 console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+
+//The error message displayed by Node.js is:
+//Uncaught ReferenceError: cityOfBirth is not defined
+//The error occurs because the variable 'cityofBirth' is used before it has been declared.

Sprint-1/2-mandatory-errors/3.js

@@ -1,9 +1,14 @@
-const cardNumber = 4533787178994213;
+const cardNumber = "4533787178994213";
 const last4Digits = cardNumber.slice(-4);
 
-// The last4Digits variable should store the last 4 digits of cardNumber
-// However, the code isn't working
-// Before running the code, make and explain a prediction about why the code won't work
+// The last4Digits variable should store the last 4 digits of cardNumber.
+// However, the code isn't working.
+// Before running the code, make and explain a prediction about why the code won't work.
 // Then run the code and see what error it gives.
 // Consider: Why does it give this error? Is this what I predicted? If not, what's different?
-// Then try updating the expression last4Digits is assigned to, in order to get the correct value
+// Then try updating the expression last4Digits is assigned to, in order to get the correct value.
+
+//The error message displayed by Node.js is:
+//Uncaught TypeError: cardNumber.slice is not a function
+//The error occurs because slice() is a string method, but the variable 'cardNumber' is a number.
+//To get the last four digits, the number must be converted to a string.

Sprint-1/2-mandatory-errors/4.js

@@ -1,2 +1,6 @@
 const 12HourClockTime = "8:53pm";
 const 24hourClockTime = "20:53";
+
+//The error message displayed by Node.js is:
+//Uncaught SyntaxError: Invalid or unexpected token
+//This error happens because JavaScript does not allow variable names to start with a number.

Sprint-1/3-mandatory-interpret/1-percentage-change.js

@@ -12,11 +12,28 @@ console.log(`The percentage change is ${percentageChange}`);
 // Read the code and then answer the questions below
 
 // a) How many function calls are there in this file? Write down all the lines where a function call is made
+// There are 5 function calls in this file. They occur on the following 3 lines:
+// carPrice = Number(carPrice.replaceAll(",", ""));
+// priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+// console.log(`The percentage change is ${percentageChange}`);
 
 // b) Run the code and identify the line where the error is coming from - why is this error occurring? How can you fix this problem?
+// The code contains one syntax error on the following line:
+// priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+// A comma is missing between the arguments inside replaceAll(). It should be:
+// priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 // c) Identify all the lines that are variable reassignment statements
+// The lines that are variable reassignment statements are as follows:
+// carPrice = Number(carPrice.replaceAll(",", ""));
+// priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
 
 // d) Identify all the lines that are variable declarations
+// The lines that contain variable declarations are as follows:
+// let carPrice = "10,000";
+// let priceAfterOneYear = "8,543";
+// const priceDifference = carPrice - priceAfterOneYear;
+// const percentageChange = (priceDifference / carPrice) * 100;
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// It removes the comma from the car price string and converts it into a number so it can be used in calculations.

Sprint-1/3-mandatory-interpret/2-time-format.js

@@ -12,14 +12,23 @@ console.log(result);
 // For the piece of code above, read the code and then answer the following questions
 
 // a) How many variable declarations are there in this program?
+// Six variables are declared in this program.
 
 // b) How many function calls are there?
+// In this program, the only function call is:
+// console.log(result);
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// The expression movieLength % 60 yields the remaining seconds after converting the total seconds into full minutes.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// It calculates the total number of full minutes in the movie length.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// It represents the movie length formatted as a time string in hours:minutes:seconds format.
+// A better name for this variable could be const formattedTime.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// The code does not produce the desired output for all possible values of movieLength.
+// It does not work correctly for decimal values.

Sprint-1/3-mandatory-interpret/3-to-pounds.js

@@ -25,3 +25,13 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 2. const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1):
+// removes the trailing "p" from the string, leaving only the numeric part ("399")
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"):
+// ensures that the numeric string has at least three characters by adding leading zeros if necessary
+// 4. const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2):
+// extracts all the digits except the last two, representing the number of pounds
+// 5. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"):
+// extracts the last two digits representing the pence
+// 6. console.log(`£${pounds}.${pence}`):
+// yields the final price in pounds and pence using the format £pounds.pence