Birmingham | 25-ITP-Sep | Joy Opachavalit | Sprint 1 | coursework/sprint-1

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

@@ -3,4 +3,4 @@ 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 is an assignment statement. The = is the assignment operator, which takes the value on the right side (count + 1, which evaluates to 1) and assigns it to the variable on the left side (count), updating count's value from 0 to 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 = `${firstName.charAt(0)}${middleName.charAt(0)}${lastName.charAt(0)}`;
+console.log(initials);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 

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

@@ -17,7 +17,10 @@ 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 ext = base.slice(base.lastIndexOf("."));
+
+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

@@ -1,9 +1,23 @@
 const minimum = 1;
 const maximum = 100;
 
-const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
+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
+
+// Breaking down what num represents:
+// num generates a random integer between 1 and 100 (inclusive)
+
+// Step-by-step evaluation:
+// 1. Math.random() → generates a decimal between 0 (inclusive) and 1 (exclusive)
+// 2. (maximum - minimum + 1) → calculates the range size: (100 - 1 + 1) = 100
+// 3. Math.random() * 100 → gives a decimal between 0 and 99.999...
+// 4. Math.floor(...) → rounds down to get integers from 0 to 99
+// 5. + minimum → shifts the range from 0-99 to 1-100
+
+// So num represents a random integer from 1 to 100

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

@@ -1,2 +1,3 @@
 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?
+By adding // at the beginning of each line to turn the text into comments.

Sprint-1/2-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-1/2-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 ?
+//The variable cityOfBirth is being used before it's declared. To fix the error, we need to declare the variable before using it in the console.log statement.
 
-console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);

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

@@ -1,9 +1,11 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = cardNumber.toString().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
-// 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
+// PREDICTION: The code won't work because cardNumber is a number, but .slice() only works on strings and arrays
+// ERROR: TypeError: cardNumber.slice is not a function
+// SOLUTION: Convert the number to a string first using .toString() method
+console.log(last4Digits); // Should output: "4213"
+//The issue is that cardNumber is a number, but the .slice() method only works on strings (and arrays).
+// Convert the number to a string first, then use .slice()

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

@@ -1,2 +1,5 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+//const 12HourClockTime = "20:53";
+//const 24hourClockTime = "08:53";
+// Variable names cannot start with a number
+const twelveHourClockTime = "20:53";
+const twentyFourHourClockTime = "08:53";

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

@@ -12,11 +12,29 @@ 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
+// 5 function calls 
+//Line 4: carPrice.replaceAll(",", "")
+//Line 4: Number(...) – wraps the above
+//Line 5: priceAfterOneYear.replaceAll(",", "") ✅ But this line has a syntax error (we’ll get to it)
+//Line 5: Number(...) – wraps the above
+//Line 10: 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?
+//syntax error! On line 5, there's a missing comma in the replaceAll method. 
+//correct code should be
+//priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 // c) Identify all the lines that are variable reassignment statements
+carPrice = Number(carPrice.replaceAll(",", ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 // d) Identify all the lines that are variable declarations
+let carPrice = "10,000";
+let priceAfterOneYear = "8,543";
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// This expression converts a string with commas into a number that can be used for mathematical calculations:
+// 1. carPrice.replaceAll(",", "") - removes all commas from the string "10,000" → "10000"
+// 2. Number(...) - converts the cleaned string "10000" into the number 10000
+// Purpose: Strings with commas cannot be used in math operations, so we need to clean and convert them to numbers first

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

@@ -12,14 +12,33 @@ 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?
+// 6 variable declarations
+//Line 1: movieLength
+//Line 3: remainingSeconds
+//Line 4: totalMinutes
+//Line 6: remainingMinutes
+//Line 7: totalHours
+//Line 9: result        
 
 // b) How many function calls are there?
+// 1 function call
+//Line 10: 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 % operator is the remainder operator. It returns the remainder left over when one operand is divided by a second operand.
+// In this case, movieLength % 60 calculates the number of seconds remaining after dividing the total movie length by 60 (the number of seconds in a minute).
+// For example, if movieLength is 8784 seconds, then 8784 % 60 equals 24, meaning there are 24 seconds left over after accounting for full minutes.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// The expression (movieLength - remainingSeconds) / 60 calculates the total number of minutes in the movie by first removing the remaining seconds and then dividing by 60 (the number of seconds in a minute).
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// The variable result represents the formatted string output of the total hours, remaining minutes, and remaining seconds of the movie.
+// A better name for this variable could be formattedMovieLength.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// The code will work for all non-negative integer values of movieLength. It correctly calculates hours, minutes, and seconds for any length of time.
+// However, if movieLength is negative or not an integer, the results may not make sense in the context of a movie length.
+// For example, if movieLength is negative, the calculations for hours, minutes, and seconds will yield negative values, which are not valid for a movie duration.
+// Additionally, if movieLength is a non-integer (e.g., a float), the calculations will still work, but the interpretation of the result may be less clear since movie lengths are typically represented as whole seconds.      

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

@@ -25,3 +25,8 @@ 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 to isolate the numeric part
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"): pads the numeric string with leading zeros to ensure it is at least 3 digits long
+// 4. const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2): extracts the pounds portion from the padded string
+// 5. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"): extracts the pence portion and ensures it is 2 digits long
+// 6. console.log(`£${pounds}.${pence}`): outputs the final formatted string representing the price in pounds

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

@@ -11,8 +11,11 @@ In the Chrome console,
 invoke the function `alert` with an input string of `"Hello world!"`;
 
 What effect does calling the `alert` function have?
+->It creat a pop up with the word "Hello world!"
 
 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?
 What is the return value of `prompt`?
+-> It displays a dialog box in the browser asking the user to enter some input.
+The user can type a response and click "OK" or click "Cancel".

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

@@ -5,12 +5,19 @@ 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?
+-> ƒ log() { [native code] }
 
 Now enter just `console` in the Console, what output do you get back?
+-> console {debug: ƒ, error: ƒ, info: ƒ, log: ƒ, warn: ƒ, …}
 
 Try also entering `typeof console`
+->'object'
 
 Answer the following questions:
 
 What does `console` store?
+->console stores an object that contains functions for outputting information to the browser’s debugging console.
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+->The . operator accesses a specific property or method on an object. console.log means "use the log function from the console object.
+console.assert means access the assert function inside the console object.