London | ITP-May-2025 | Surafel Workneh | Structuring and testing data | Coursework/sprint 1

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

@@ -2,5 +2,7 @@ let count = 0;
 
 count = count + 1;
 
+console.log(count); // Output: 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 reassigning the count variable to a new value which is the current value increment by 1, "=" is assigning operator that assigning value of right side which mens count increment 1 to the left side value of count variable

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

@@ -1,11 +1,17 @@
 let firstName = "Creola";
 let middleName = "Katherine";
 let lastName = "Johnson";
+// The code above declares these three variables: firstName, middleName, and lastName.
+// Each variable is assigned a string value representing each element in the name.
+// The task is to create a new variable take initials that combines the first character from each of these strings.
+// The initials variable should contain the first letter of each name, resulting in the string "CKJ".
 
 // 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 = ``;
-
+initials = firstName[0] + middleName[0] + lastName[0];
+console.log(initials); // Output: CKJ
+// The code above uses the bracket notation to access the first character of each string [0].
+// This is a common way to get the first character of a string in JavaScript.
 // https://www.google.com/search?q=get+first+character+of+string+mdn
-

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

@@ -12,12 +12,12 @@
 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 = ;
-
-// https://www.google.com/search?q=slice+mdn
+const ext=base.slice(base.lastIndexOf(".") + 1); // The code uses the lastIndexOf method to find the position of the last dot in the base variable.
+// Create a variable to store the dir part of the filePath variable
+const dir = filePath.slice(0, lastSlashIndex);// The code uses the lastIndexOf method to find the position of the last slash in;
+filePath.slice(0, lastSlashIndex);
+console.log(`The dir part of ${filePath} is ${dir}`);
+console.log(`The base part of ${filePath} is ${base}`);
+console.log(`The ext part of ${filePath} is ${ext}`); 

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

@@ -7,3 +7,10 @@ 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(num);
+// Output: A random number between 1 and 100 (inclusive both 1 and 100)
+//num is a random number generated between the minimum 1 and maximum values 100.
+// The expression Math.random() generates a random floating-point number between [0,1).
+// The expression (maximum - minimum + 1) calculates the range of numbers we want to generate, which is 100 - 1 + 1 = 100.
+// The expression Math.floor() rounds down the result to the nearest whole number.
+// Finally, we add the minimum value to ensure that the random number falls within the desired range.

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

@@ -2,3 +2,6 @@
 
 const age = 33;
 age = age + 1;
+console.log(age); // Output: 34
+// The code above declares a variable age with an initial value of 33.
+// It then reassigns the value of age by adding 1 to its current value, so the declaration must be using 'let' keyword.

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

@@ -1,5 +1,7 @@
 // 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}`);
+
+//The error is that the variable cityOfBirth is being used before it has been declared.JavaScript executes code line by line from top to bottom, so you must declare and assign a value to the variable before using it.
+// In JavaScript, variables declared with let or const are not hoisted, meaning they cannot be accessed before their declaration.

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

@@ -1,5 +1,10 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+// Prediction: The code will not work because the `slice` method is being called on a number type (`cardNumber`),
+// and the `slice` method is a string method. In JavaScript, numbers do not have a `slice` method.
+// Running the code will likely result in a TypeError.
+
+const last4Digits = cardNumber.toString().slice(-4); // Convert cardNumber to a string first
+console.log(`The last 4 digits of the card number are ${last4Digits}`);
 
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working

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

@@ -1,2 +1,34 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+// const 12HourClockTime = "20:53"; it is in 24 hour format
+// const 24hourClockTime = "08:53"; it is in 12 hour format then we will write correctly
+// const twelveHourClockTime = "08:53 PM"; // Example 12-hour format time
+// const twentyFourHourClockTime = "20:53"; // Example 24-hour format time
+
+const twelveHourClockTime = "08:53 PM"; // Example 12-hour format time
+const twentyFourHourClockTime = "20:53"; // Example 24-hour format time
+function convertTo12HourClockTime(time24clock) {
+  let [hours, minutes] = time24clock.split(":").map(Number);
+  const modifier = hours >= 12 ? "PM" : "AM";
+
+  if (hours === 0) {
+    hours = 12; // Midnight case
+  } else if (hours > 12) {
+    hours -= 12; // Convert to 12-hour format
+  }
+
+  return `${hours.toString().padStart(2, "0")}:${minutes.toString().padStart(2, "0")} ${modifier}`;
+}
+function convertTo24HourClockTime(time12clock) {
+  let [time, modifier] = time12clock.split(" ");
+  let [hours, minutes] = time.split(":").map(Number);
+
+  if (modifier === "PM" && hours !== 12) {
+    hours += 12;
+  } else if (modifier === "AM" && hours === 12) {
+    hours = 0;
+  }
+
+  return `${hours.toString().padStart(2, "0")}:${minutes
+    .toString()
+    .padStart(2, "0")}`;
+}
+console.log(convertTo12HourClockTime(twentyFourHourClockTime)); // Output: "08:53 PM"

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
-
+// There are 5 function calls in this file. The code consists of variable assignments and calculations without any function definitions or calls.
+// replaceAll(",", "") (twice)
+// Number(...) (twice)
+// console.log(...) (once)
 // 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?
+// There are no errors in the code. The code runs successfully and calculates the percentage change in car price without any issues.
 
 // c) Identify all the lines that are variable reassignment statements
+// The variable reassignment statements are:
+// 1. carPrice = Number(carPrice.replaceAll(",", ""));
+// 2. priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 // d) Identify all the lines that are variable declarations
-
+// The variable declarations are:
+// 1. let carPrice = "10,000";
+// 2. let priceAfterOneYear = "8,543";
+// 3. const priceDifference = carPrice - priceAfterOneYear;
+// 4. const percentageChange = (priceDifference / carPrice) * 100;
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// The expression `Number(carPrice.replaceAll(",", ""))` is converting the string representation of the car price, which includes commas (e.g., "10,000"), into a number. The `replaceAll(",", "")` part removes all commas from the string, resulting in "10000", and then the `Number()` function converts this string into a numeric value (10000). This is necessary for performing arithmetic operations on the price.

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

@@ -1,4 +1,4 @@
-const movieLength = 8784; // length of movie in seconds
+const movieLength = 9000; // length of movie in seconds
 
 const remainingSeconds = movieLength % 60;
 const totalMinutes = (movieLength - remainingSeconds) / 60;
@@ -12,14 +12,27 @@ 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
+// 1. movieLength
+// 2. remainingSeconds
+// 3. totalMinutes
+// 4. remainingMinutes
+// 5. totalHours
+// 6. result
 
 // b) How many function calls are there?
+// their is 1 function call
+// console.log(result);
 
-// c) Using documentation, explain what the expression movieLength % 60 represents
+// c) Using documentation, explain what the expression movieLength % 60 represents The is expressing remaining number of seconds after converted to 60 seconds
+// The expression `movieLength % 60` calculates the remainder when `movieLength` (the length of the movie in seconds)
+// This gives the number of seconds that do not complete a full minute, effectively representing the remaining seconds after converting the total movie length into minutes.
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
-
+// The expression (movieLength - remainingSeconds) / 60 determines the total number of full minutes in the movie by removing the leftover seconds and then dividing the result by 60.
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
-
+//time
+// The variable `result` represents the formatted time of the movie in the format "hours:minutes:seconds".
+// A better name for this variable could be "movieDuration" to make it clearer that it holds the duration of the movie in a specific format.
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer

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

@@ -1,4 +1,4 @@
-const penceString = "399p";
+const penceString = "5p";
 
 const penceStringWithoutTrailingP = penceString.substring(
   0,
@@ -13,7 +13,6 @@ const pounds = paddedPenceNumberString.substring(
 
 const pence = paddedPenceNumberString
   .substring(paddedPenceNumberString.length - 2)
-  .padEnd(2, "0");
 
 console.log(`£${pounds}.${pence}`);
 
@@ -24,4 +23,9 @@ 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": initialize a string variable with the value "399p"
+//2. Removes the trailing "p" from the string: and result will be 399
+//3. Ensures the number has at least 3 digits by padding from the left with zeros: like 000
+//4. Extracts the pound portion: "3"
+//5.Extracts the pound portion: "99"
+//6. Extracts the pound portion: in the standard monetary format of pounds and pence: "£3.99"

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?
+This displays a popup box (called an "alert dialog") in the browser with the message: '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?
+A popup input box appears asking: "What is your name?"
 What is the return value of `prompt`?
+Shows input dialog

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

@@ -5,12 +5,15 @@ 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?
-
-Try also entering `typeof console`
+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?
-What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+What does `console` store? different functions (methods) like s log messages, show errors, warnings
+
+What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?`console.log` means accessing 'log' function inside 'console' object
+`console.assert` mean accessing 'assert' function inside 'console' object
+`.` is the dot notation and It’s used to access properties or methods of an object.