West Midlands | ITP-Sept-2025 | Ali Naru | Sprint 3 | Coursework/sprint-1

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

@@ -4,3 +4,8 @@ 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 is updating the value of the count variable by adding 1 to its current value.
+//  The = operator is used for assignment, meaning it takes the result of the expression on the right (count + 1) and assigns that new value back to the count variable.

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

@@ -5,7 +5,9 @@ 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 = `${firstName[0]}${middleName[0]}${lastName[0]}`;
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 
+console.log(initials);  
+// Should print "CKJ"

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

@@ -1,4 +1,4 @@
-// The diagram below shows the different names for parts of a file path on a Unix operating system
+/// The diagram below shows the different names for parts of a file path on a Unix operating system
 
 // ┌─────────────────────┬────────────┐
 // │          dir        │    base    │
@@ -7,17 +7,27 @@
 // "  /    home/user/dir / file  .txt "
 // └──────┴──────────────┴──────┴─────┘
 
-// (All spaces in the "" line should be ignored. They are purely for formatting.)
-
 const filePath = "/Users/mitch/cyf/Module-JS1/week-1/interpret/file.txt";
+
+// Find last slash to separate dir and base
 const lastSlashIndex = filePath.lastIndexOf("/");
+
+// base = name + ext (e.g. "file.txt")
 const base = filePath.slice(lastSlashIndex + 1);
 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
+// dir = everything before the last slash
+const dir = filePath.slice(0, lastSlashIndex);
+
+// Find last dot to extract only extension
+const lastDotIndex = filePath.lastIndexOf(".");
+
+// ext = everything from the last dot onward
+const ext = filePath.slice(lastDotIndex);
+
+console.log(`The dir part of ${filePath} is ${dir}`);
+console.log(`The ext part of ${filePath} is ${ext}`);
+
+// https://www.google.com/search?q=slice+mdn
 
-const dir = ;
-const ext = ;
 
-// https://www.google.com/search?q=slice+mdn

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

@@ -1,9 +1,11 @@
-const minimum = 1;
-const maximum = 100;
+// MIN and MAX are constants that define the lower and upper bounds for our random number range.
+const MIN = 1;
+const MAX = 10;
 
-const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
+// Math.random() returns a decimal value in the interval [0, 1)
+// Multiplying by (MAX - MIN + 1) scales the interval to [0, MAX - MIN + 1)
+// Applying Math.floor() converts the value to an integer within [s0, MAX - MIN]
+// Finally, adding MIN shifts the interval to [MIN, MAX], which is our desired result.
 
-// 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
+const num = MIN + Math.floor(Math.random() * (MAX - MIN + 1));
+console.log(num);

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

@@ -1,2 +1,4 @@
-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?
+///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?
+
+// in code use backslashes to create comments.

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

@@ -1,4 +1,8 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33; // changed from constant to variable so that value can be reassigned
 age = age + 1;
+console.log(age); // should print 34 running testing 
+
+
+//after testing can confirm age variable is now 34.

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

@@ -3,3 +3,6 @@
 
 console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+
+
+// Code is executed line by line so the variable cityOfBirth is not defined when it is called in the console.log line.

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

@@ -1,9 +1,18 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+//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
+// CardNumber is not a funtion so it does not have the method slice.
+
 // Then run the code and see what error it gives.
+// TypeError: cardNumber.slice is not a function
 // Consider: Why does it give this error? Is this what I predicted? If not, what's different?
+//this is what I predicted because slice is a method for strings and arrays, not numbers.
 // Then try updating the expression last4Digits is assigned to, in order to get the correct value
+
+
+const last4DigitsCorrected = cardNumber.toString().slice(-4);
+
+console.log(last4DigitsCorrected); // Should output: 4213

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

@@ -1,2 +1,6 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const twelveHourClockTime = "20:53";
+const twentyFourHourClockTime = "08:53";
+
+
+//Variables cannot have numbers at the start of their name
+//the times are in the wrong format for their variable names

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

@@ -2,21 +2,24 @@ let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
 carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 const priceDifference = carPrice - priceAfterOneYear;
 const percentageChange = (priceDifference / carPrice) * 100;
 
 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 five function calls: carPrice.replaceAll(",", ""), Number(carPrice.replaceAll(",", "")), priceAfterOneYear.replaceAll(",", ""), Number(priceAfterOneYear.replaceAll(",", "")), and console.log(...).
 
 // 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 error comes from the line priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," "")); because there is a missing comma between the arguments in replaceAll, which causes a syntax error. It can be fixed by writing replaceAll(",", "") instead.
 
 // c) Identify all the lines that are variable reassignment statements
+// The variable reassignment statements are carPrice = Number(carPrice.replaceAll(",", "")); and priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));.
 
 // d) Identify all the lines that are variable declarations
+// The variable declarations are let carPrice = "10,000";, let priceAfterOneYear = "8,543";, const priceDifference = carPrice - priceAfterOneYear;, and const percentageChange = (priceDifference / carPrice) * 100;.
 
-// e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// e) Describe what the expression Number(carPrice.replaceAll(",", "")) is doing - what is the purpose of this expression?
+// The expression first removes the comma from the string "10,000" using replaceAll(",", ""), resulting in "10000", and then converts that string into a number using Number(), so that it can be used in mathematical calculations.

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

@@ -9,17 +9,20 @@ const totalHours = (totalMinutes - remainingMinutes) / 60;
 const result = `${totalHours}:${remainingMinutes}:${remainingSeconds}`;
 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?
+// There are six variable declarations: movieLength, remainingSeconds, totalMinutes, remainingMinutes, totalHours, and result.
 
 // b) How many function calls are there?
+// There is one function call in this program: 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 uses the modulo (%) operator to find the remainder after dividing movieLength by 60. This gives the number of seconds left over after converting all full minutes from the total seconds.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// The expression (movieLength - remainingSeconds) / 60 converts the total number of seconds (minus any leftover seconds) into full minutes, effectively giving the total number of complete minutes in the movie.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// The variable result represents the movie length converted from seconds into hours, minutes, and seconds in the format "hours:minutes:seconds". A better name for this variable would be formattedDuration or timeString for clarity.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// This code works correctly for positive integer values of movieLength because it cleanly divides seconds into hours, minutes, and seconds. However, it will not work properly for negative numbers or non-integer values, and it doesn’t add leading zeros (e.g. it might print 2:5:3 instead of 2:05:03).

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

@@ -17,11 +17,9 @@ const pence = paddedPenceNumberString
 
 console.log(`£${pounds}.${pence}`);
 
-// This program takes a string representing a price in pence
-// The program then builds up a string representing the price in pounds
-
-// You need to do a step-by-step breakdown of each line in this program
-// Try and describe the purpose / rationale behind each step
-
-// To begin, we can start with
-// 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 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 by taking all characters from index 0 up to but not including the last one, leaving "399". This isolates the numeric part of the price.
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"): ensures the numeric string has at least three digits by adding leading zeros if needed (for example, "5p" becomes "005"). This makes it easier to separate pounds and pence later.
+// 4. const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2): extracts all digits except the last two to represent the pounds. For "399" this gives "3".
+// 5. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"): takes the last two digits of the string as pence, and if needed, pads the end with a zero to ensure two digits. For "399" this gives "99".
+// 6. console.log(`£${pounds}.${pence}`): prints the formatted price as a string in the style of "£3.99". The program as a whole converts a pence-based string like "399p" into a properly formatted pounds and pence display.