London | 25-ITP-SEP | Mariia Serhiienko| Sprint 1 | Module-Structuring-and-Testing Data Coursework

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

@@ -4,3 +4,7 @@ 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 an assignment operator that assigns the result of the expression on the right (count + 1) to the variable on the left (count).
+// So after line 3 executes, count will have a new value of 1.
+// = does not mean “equal to” (as in math); it means “take the value on the right and store it in the variable on the left.”

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); // Output: "CKJ"
 
+// 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(1, lastSlashIndex);
+const ext = filePath.slice(filePath.lastIndexOf("."));
 
-// https://www.google.com/search?q=slice+mdn
+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

@@ -7,3 +7,22 @@ const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 // 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
+
+console.log(`Random number between ${minimum} and ${maximum}: ${num}`);
+
+console.log(
+  "Random number between 0 and 1 after evaluating Math.random() is: ",
+  Math.random()
+);
+console.log(
+  "Math.random() * (maximum - minimum + 1) scales the range from 1 to 100 (100 isn't included) for the random number: ",
+  Math.random() * (maximum - minimum + 1)
+);
+console.log(
+  "Math.floor(Math.random() * (maximum - minimum + 1)) rounds down the random number: ",
+  Math.floor(Math.random() * (maximum - minimum + 1))
+);
+console.log(
+  "(Math.floor(Math.random() * (maximum - minimum + 1)) + minimum)  shifts the range to 1–100 (100 is included): ",
+  Math.floor(Math.random() * (maximum - minimum + 1)) + minimum
+);

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

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

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

@@ -1,5 +1,5 @@
 // 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-1/2-mandatory-errors/3.js

@@ -1,9 +1,10 @@
 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
+console.log(`The last 4 digits of the card number are: ${last4Digits}`);

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

@@ -1,2 +1,2 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const _12HourClockTime = "20:53";
+const hour24ClockTime = "08:53";

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 +12,23 @@ 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
+// Line 4: Number(), carPrice.replaceAll(",", "") - 2 function calls
+// Line 5: Number(), priceAfterOneYear.replaceAll(",", "") - 2 function calls
+// Line 10: console.log() - 1 function call
+// In total: 5 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?
+// Its line 5 - missed comma in replaceAll method. Fixed now - added comma after the first parameter.
 
 // c) Identify all the lines that are variable reassignment statements
+// Line 4: carPrice = Number(carPrice.replaceAll(",", ""));
+// Line 5: priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 // 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;
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// This expression transforms data type from String to Number and removes all commas from the String value of carPrice, so "10,000" becomes "10000".

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

@@ -1,4 +1,4 @@
-const movieLength = 8784; // length of movie in seconds
+const movieLength = 8468; // length of movie in seconds
 
 const remainingSeconds = movieLength % 60;
 const totalMinutes = (movieLength - remainingSeconds) / 60;
@@ -12,14 +12,25 @@ 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?
+// 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
+// This expression calculates the remainder or modulo when movieLength (in seconds) is divided by 60. This gives the number of seconds remaining after converting the total seconds into full minutes.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// It means the total number of full minutes in the movie length. It subtracts the remaining seconds from the total movie length and then divides that value by 60 to convert it from seconds to minutes.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// It represents the formatted string of the movie length in hours, minutes and seconds. A better name could be formattedMovieTime or durationMovieFormatted.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+//Code works correctly, but there are few edge cases to consider:
+// 1. If movieLength is negative, the output won't make sense in the context of time duration.
+// 2. If movieLength is a very large number the output'll still be correct, but not readable - "1.7968563299644136e+35:4:52"
+// 3. If movieLength is zero, the output will be "0:0:0", which is valid but may not be the desired format for representing zero duration.
+// 4. If movieLength is not an integer like floating-point number, the calculations may yield unexpected results - "2:21:8.299999999999272" since time is typically represented in whole seconds.
+// 5. When hours, minutes or seconds are single digits (1:5:3) the output may not be in the desired format with 2digits - "01:05:03".

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

@@ -24,4 +24,9 @@ console.log(`£${pounds}.${pence}`);
 // 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": initializes a string variable with the value "399p"
+// 2. const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1): creates a copy of the penceString and method substring() removes the last character 'p', using the length of the original string minus 1 as the endpoint
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"): ensures that the string has at least 3 characters, if not - adds zeros to the start of the string until it reaches that length. Method padStart() is used for this purpose - padStart(targetLength, padString), where targetLength is 3 and padString is "0". If string is already 3 or more characters long, no symbol is added.
+// 4. const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2): extracts the pounds from the paddedPenceNumberString by taking all characters except the last two, using substring() method with the endpoint set to the length of the string minus 2
+// 5. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"): extracts the last two characters with method substring() from the paddedPenceNumberString to represent the pence (starting index set to the length of the string minus 2). Then, padEnd(2, "0") ensures that the resulting string has at least 2 characters, adding a trailing zero if necessary.
+// 6. console.log(`£${pounds}.${pence}`): outputs the formatted amount of money/price in pounds and pence to the console, using template literals for nice readable view (it allowed combining the pounds and pence with the appropriate currency symbol and decimal point.

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

@@ -12,7 +12,14 @@ invoke the function `alert` with an input string of `"Hello world!"`;
 
 What effect does calling the `alert` function have?
 
+- It shows a modal pop-up box with phrase `"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`?
+
+- The browser shows the pop-up dialogue box with the question `"What is your name?"`, two buttons "Cancel" and "Ok" and text input field where user can type their name
+
+## What is the return value of `prompt`?
+
+- If user typed something in the text input field - that'll be the return value with data type String, even if user typed numbers. If user pressed "Cancel" button, then value'll be null. If user pressed "Ok" button but didn't type anytning then value'll be an empty string - ""

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

@@ -6,11 +6,20 @@ 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`
 
 Answer the following questions:
 
 What does `console` store?
-What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+
+- It stores functions/methods
+  What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+  - `console.log` means “get the log property from the console object.”
+  - `console.assert` means “get the assert property from the console object.”
+  - `.` is the property access operator, it lets us access specific functions or values that belong to an object.

prep/prep-sprint-1.js

@@ -0,0 +1,17 @@
+// 1.Write a function that will calculate the area of a rectangle. The function should take two parameters: length and width. It should return the area of the rectangle.
+
+function calculateArea(length, width) {
+  const area = length * width;
+  return area;
+}
+
+console.log(calculateArea(3, 4)); // Output: 12
+
+// 2.Write a function that will capitalize the first letter in a given string.
+
+function capitalizeFirstLetter(name) {
+  const result = name[0].toUpperCase() + name.slice(1);
+  return result;
+}
+
+console.log(capitalizeFirstLetter("mario")); // Output: "Mario"