Manchester | 26-ITP-Sep | Salah Alsabhi | Sprint 2 | Coursework

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

@@ -3,4 +3,6 @@ let count = 0;
 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: first it calculates count + 1 (using the current value of count),
+// then the = assignment operator stores that new result back into the count variable.
+// So count changes from 0 to 1.

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

@@ -5,6 +5,8 @@ const 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.
 
-const initials = ``;
+const initials = `${firstName.charAt(0)}${middleName.charAt(0)}${lastName.charAt(0)}`;
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
+
+console.log(initials)                                                                                                                                       

Sprint-2/1-key-exercises/3-paths.js

@@ -17,7 +17,9 @@ 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);
+console.log(dir);
+const dotIndex = base.lastIndexOf(".");
+const ext = base.slice(dotIndex);
 
-// https://www.google.com/search?q=slice+mdn
+// https://www.google.com/search?q=slice+mdn

Sprint-2/1-key-exercises/4-random.js

@@ -2,8 +2,10 @@ const minimum = 1;
 const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
+console.log(num);
 
 // 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
+// num is a random whole number between 1 and 100

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

@@ -1,2 +1,2 @@
-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?

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

@@ -1,4 +1,5 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
+console.log(age);

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

@@ -1,5 +1,6 @@
 // Currently trying to print the string "I was born in Bolton" but it isn't working...
 // what's the error ?
 
-console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);
+

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

@@ -1,9 +1,12 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = String(cardNumber).slice(-4);
+console.log(last4Digits);
+
 
 // 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
+//updated expression last4Digits to a String.

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

@@ -1,2 +1,6 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const clockTime12Hour = "8:53pm";
+const clockTime24Hour = "20:53";
+console.log(clockTime12Hour);
+console.log(clockTime24Hour);
+
+//variable names can not start with numbers

Sprint-2/3-mandatory-interpret/1-percentage-change.js

@@ -2,21 +2,35 @@ 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}`);
+console.log(`The price difference is ${priceDifference}`);
+
+
+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
+// Answer: 6 function calls.
 
 // 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?
+// Answer: line 5 {replaceAll(",", ""))} added , to fix the SyntaxError.
 
 // c) Identify all the lines that are variable reassignment statements
+// Answer: carPrice = Number(carPrice.replaceAll(",", "")); line 4
+//         priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", "")); line 5
 
 // d) Identify all the lines that are variable declarations
+// Answer: let carPrice = "10,000"; line1
+//         let priceAfterOneYear = "8,543"; line 2
+//         const priceDifference = carPrice - priceAfterOneYear; line 7
+//         const percentageChange = (priceDifference / carPrice) * 100; line 8
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// Answer: carPrice.replaceAll(",","") remove commas from the string.
+//         Number(...) changes the text to a number so subtraction and division work correctly.
+

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

@@ -1,4 +1,4 @@
-const movieLength = 8784; // length of movie in seconds
+const movieLength = 9325; // length of movie in seconds
 
 const remainingSeconds = movieLength % 60;
 const totalMinutes = (movieLength - remainingSeconds) / 60;
@@ -12,14 +12,32 @@ 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?
+// Answer: 6 variable declarations.
 
 // b) How many function calls are there?
+// Answer: 1 function call.
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// Answer: The % operator is the remainder (modulo) operator.
+// movieLength % 60 gives the remainder after dividing the total seconds by 60.
+// That remainder is the number of seconds left after removing complete minutes.
+// Example: 8784 % 60 === 24.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// Answer: (movieLength - remainingSeconds) / 60
+// First it subtracts the leftover seconds so the value divides evenly by 60,
+// then it divides by 60 to get the total number of whole minutes in the movie.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// Answer: result stores the movie length formatted as hours:minutes:seconds
+// (for this value: "2:26:24").
+// A clearer name would be formattedTime.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// Answer: It works for non-negative whole numbers of seconds and correctly
+// splits time into hours, minutes, and seconds.
+// Limitations:
+// - fractional values can produce messy decimals
+// - negative values do not make sense for a movie length.
+// Note: I have changed the movieLength from "8784" to "9325" for testing.

Sprint-2/3-mandatory-interpret/3-to-pounds.js

@@ -23,5 +23,39 @@ console.log(`£${pounds}.${pence}`);
 // 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"
+//Answer:
+
+// 1. const penceString = "399p"
+//    Initialises a string variable with the value "399p"
+//    (price written in pence, with a trailing "p").
+
+// 2. penceString.substring(0, penceString.length - 1)
+//    Removes the final character "p".
+//    For "399p" this becomes "399".
+//    Stored in penceStringWithoutTrailingP.
+
+// 3. penceStringWithoutTrailingP.padStart(3, "0")
+//    Ensures the string is at least 3 characters long by padding
+//    with "0" on the left if needed.
+//    "399" stays "399".
+//    Example: "5" would become "005", "42" would become "042".
+//    This makes it easier to always treat the last 2 digits as pence.
+
+// 4. paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2)
+//    Takes everything except the last 2 characters → the pounds part.
+//    For "399" this is "3".
+
+// 5. paddedPenceNumberString.substring(paddedPenceNumberString.length - 2)
+//    Takes only the last 2 characters → the pence part.
+//    For "399" this is "99".
+
+// 6. .padEnd(2, "0") on the pence part
+//    Ensures pence is always 2 digits (adds "0" on the right if needed).
+//    "99" stays "99".
+//    Example: if pence were "5", it would become "50" with padEnd —
+//    (note: for money, padStart is usually more common for the numeric part;
+//    here the code uses padEnd as written).
+
+// 7. console.log(`£${pounds}.${pence}`)
+//    Prints the final price in pounds format.
+//    For this input: £3.99

Sprint-2/4-stretch-explore/chrome.md

@@ -13,3 +13,7 @@ Now try invoking the function `prompt` with a string input of `"What is your nam
 
 What effect does calling the `prompt` function have?
 What is the return value of `prompt`?
+## Answers
+- alert("Hello world!") shows a browser alert dialog with that message.
+- prompt("What is your name?") shows an input dialog asking for a name.
+- prompt returns the typed string if OK is pressed, or null if Cancel is pressed.

Sprint-2/4-stretch-explore/objects.md

@@ -14,3 +14,9 @@ Answer the following questions:
 
 What does `console` store?
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+## Answers
+- console.log is a function (native code).
+- console is an object containing logging methods.
+- typeof console is "object".
+- console stores the browser/devtools console API object.
+- The dot `.` means property access: console.log is the log property (a function) on the console object.