Manchester | 25-ITP-May | Jennifer Isidienu | Sprint 1 | Coursework

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

@@ -4,3 +4,9 @@ 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 value on the right (count + 1) 
+// and assigns it to the variable on the left (count).
+// The expression count + 1 calculates the new value, and the = operator updates 
+// the count variable with this new value.
+// The final value of the count variable is now 1.   

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

@@ -5,7 +5,8 @@ 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); // "CKJ"

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

@@ -12,12 +12,19 @@
 const filePath = "/Users/mitch/cyf/Module-JS1/week-1/interpret/file.txt";
 const lastSlashIndex = filePath.lastIndexOf("/");
 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
 
-const dir = ;
-const ext = ;
+// Get the directory path (everything before the base)
+const dir = filePath.slice(0, lastSlashIndex);
+
+// Get the extension (everything after the last dot in the base)
+const lastDotIndex = base.lastIndexOf(".");
+const ext = base.slice(lastDotIndex);
+
+console.log(`The base part of ${filePath} is ${base}`);
+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

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

@@ -2,8 +2,15 @@ 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 integer between 1 and 100
+// The expression Math.random() generates a random floating-point number between 0 (inclusive) and 1 (exclusive).
+// Multiplying this by (maximum - minimum + 1) scales the range to the desired size.
+// Adding minimum shifts the range to start at the minimum value.

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?
+We don't want the computer to run these 2 lines - how can we solve this problem?
+
+We can use comment to ignore the two lines so the computer doesn't run them.

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

@@ -1,4 +1,7 @@
-// trying to create an age variable and then reassign the value by 1
 
-const age = 33;
-age = age + 1;
+// Trying to create an age variable and then reassign the value by 1
+
+let age = 33;      // Create a changeable variable
+age = age + 1;     // Increase the value by 1
+
+console.log("New age:", age);

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

@@ -1,5 +1,12 @@
 // 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}`);
+// console.log(`I was born in ${cityOfBirth}`);
+// const cityOfBirth = "Bolton";
+
+// The error occurs because the variable `cityOfBirth` is being used before it has been declared.
+// In JavaScript, variables declared with `const` must be initialized before they can be used.
+// To fix this, we need to declare the variable before using it in the console.log statement.
+
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);

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

@@ -1,9 +1,21 @@
 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
+
+// The code will not work because `cardNumber` is a number, 
+// and the `slice` method is not available on numbers. 
+// The `slice` method is a string method, so we need to convert 
+// `cardNumber` to a string first.
+// The prediction is correct, and the error stated:
+// cardNumber.slice is not a function"
+// After converting `cardNumber` to a string, the code now works correctly.
+// The last4Digits variable now correctly stores the last 4 digits of cardNumber
+// The Output is "4213"

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

@@ -1,2 +1,5 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const twelveHourClockTime = "08:53";
+const twentyFourHourClockTime = "20:53";
+
+console.log("12-hour clock time:", twelveHourClockTime);
+console.log("24-hour clock time:", twentyFourHourClockTime);

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

@@ -2,7 +2,7 @@ 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;
@@ -12,11 +12,38 @@ 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:
+// 1. `Number(carPrice.replaceAll(",", ""))`  Line 4
+// 2. `carPrice.replaceAll(",", ""))`  Line 4
+// 3. `Number(priceAfterOneYear.replaceAll(",", ""))` Line 5
+// 4. `priceAfterOneYear.replaceAll(",", "")` Line 5
+// 5. `console.log(...)` Line 10
 
 // 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 is on line 5: 
+// `priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));`
+// It occured because there is a missing comma between arguments in replaceAll()
+// To fix this, change it to `replaceAll(",", "")` without the space.
+// The corrected line should be:
+// `priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));`
+
 
 // c) Identify all the lines that are variable reassignment statements
+// Line 4: `carPrice = Number(carPrice.replaceAll(",", ""));`
+// Line 5: `priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));`
+// Lines 4 and 5 are variable reassignment statements because they were first 
+// declared in lines 1 and 2.
 
 // d) Identify all the lines that are variable declarations
+// Line 1: `let carPrice = "10,000";`
+// Line 2: `let priceAfterOneYear = "8,543";`
+// Line 7: `const priceDifference = carPrice - priceAfterOneYear;`
+// Line 8: `const percentageChange = (priceDifference / carPrice) * 100;`
+// Lines 1,2, 7 and 8 are variable declarations because they introduce new variables
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// The expression is converting the string representation of a car price, 
+// which includes commas, into a number.
+// It first removes the commas from the string using `replaceAll(",", "")`
+// and then converts the string into a number using the `Number()` function.
+

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

@@ -12,14 +12,40 @@ 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 6 variable declarations: movieLength, remainingSeconds, 
+// totalMinutes, remainingMinutes, totalHours and result.
 
 // b) How many function calls are there?
+// There is 1 function call: 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 calculates the remainder when movieLength 
+// is divided by 60.
+// It is used to find the remaining seconds after converting the total 
+// movie length from seconds to minutes.
+// for instance, if movieLength is 8784 seconds, 
+// the expression 8784 % 60 will return 24, 
+// because 8784 divided by 60 is 146 with a remainder of 24.
+// the expression will return 24, which means there are 24 seconds left after
+// converting the total movie length to minutes 
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// The expression assigned to totalMinutes converts the total movie length 
+// from seconds to minutes by removing the remaining seconds and dividing by 60.
+// For example, if movieLength is 8784 seconds,
+// the expression (8784 - 24) / 60 will return 146,
+// which means the movie is 146 minutes long.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// The variable result represents the total movie length showing in
+// "hours, minutes and seconds". 
+// A better name could be movieDuration.
+
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// Yes, this code will work for all values of movieLength.
+// The code can handle any positive integer value for movieLength.
+// It will correctly calculate the total hours, minutes, and seconds except
+// for negative or decimal values.
+

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

@@ -25,3 +25,21 @@ 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.
+
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0")
+// : pads the string with leading zeros to ensure it has at least 3 characters.
+
+// 4. const pounds = paddedPenceNumberString.substring
+// (0, paddedPenceNumberString.length - 2): extracts the pounds part of the string
+//  by taking all characters except the last two because it represents the pence.
+
+// 5. const pence = paddedPenceNumberString.substring
+// (paddedPenceNumberString.length - 2).padEnd(2, "0"): 
+// extracts the pence part of the string by taking the last two characters 
+// and ensuring it has exactly 2 characters by padding with zeros if necessary.
+
+// 6. console.log(`£${pounds}.${pence}`): prints the final formatted string 
+// in pounds and pence e.g. £3.99.

Sprint-1/4-stretch-explore/chrome.md

@@ -11,8 +11,12 @@ In the Chrome console,
 invoke the function `alert` with an input string of `"Hello world!"`;
 
 What effect does calling the `alert` function have?
+It creates a popup message box in the browser that displays the message.
 
 Now try invoking the function `prompt` with a string input of `"What is your name?"` - store the return value of your call to `prompt` in an variable called `myName`.
 
 What effect does calling the `prompt` function have?
+It shows a popup dialog with a text input field and message. Also, the user can type something and press OK or Cancel.
+
 What is the return value of `prompt`?
+Once the user types something and clicks OK, the input text is returned as a string. If the user clicks Cancel, it returns null.

Sprint-1/4-stretch-explore/objects.md

@@ -5,12 +5,22 @@ In this activity, we'll explore some additional concepts that you'll encounter i
 Open the Chrome devtools Console, type in `console.log` and then hit enter
 
 What output do you get?
+The output is:
+ƒ log() { [native code] }
 
 Now enter just `console` in the Console, what output do you get back?
+The output is: console {debug: ƒ, error: ƒ, info: ƒ, log: ƒ, warn: ƒ, …}
 
 Try also entering `typeof console`
+The output is:'object'
 
 Answer the following questions:
 
 What does `console` store?
+It stores function for logging information, debugging and displaying messages in the browser's developer console.
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+`console.log` means to use the log function that belongs to the console object to print messages to the console.”
+`console.assert` means to use the assert method from the console object to test if something is true.
+The `.` is called dot notation and it is used It is used in javascript to access properties or methods of an object.
+