ITP JAN 2025 LONDON| ELFREDAH KEVIN-ALERECHI |Structuring-and-Testing-Data| SPRINT 1

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

@@ -4,3 +4,18 @@ 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 count. Therefore, line 3 is just increasing the value of count by 1.
+
+
+//RESPONSE VELOW
+Line 3: count = count + 1;
+This line updates the value of the count variable by increasing it by 1.
+
+The = in this line is the assignment operator, not a comparison operator. It assigns the value on the right-hand side to the variable on the left-hand side.
+
+So count + 1 is evaluated first (which gives 1, since count was 0).
+
+Then the result (1) is assigned back to the variable count.
+
+So overall, Line 3 means:
+“Take the current value of count, add 1 to it, and store the new value back in count.”

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

@@ -1,11 +1,11 @@
-let firstName = "Creola";
-let middleName = "Katherine";
-let lastName = "Johnson";
+let firstName = "Elfredah";
+let middleName = "Kevin";
+let lastName = "Alerechi";
 
 // 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
 

Sprint-1/1-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 = ;
+//SOLUTIONS BELOW
+
+const dir ="filePath.slice(0, lastSlashIndex)";
+const ext = base.split(".").pop();
 
 // https://www.google.com/search?q=slice+mdn

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

@@ -7,3 +7,46 @@ 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
+
+//solutions below:
+
+const minimum = 1;
+const maximum = 100;
+
+const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
+ What is num?
+num ends up being a random integer between minimum (1) and maximum (100) — inclusive of both 1 and 100.
+
+//Let's break down the expression:
+
+Math.floor(Math.random() * (maximum - minimum + 1)) + minimum
+Math.random()
+
+This generates a random decimal number between 0 (inclusive) and 1 (exclusive).
+
+Example output: 0.472, 0.9999, 0.015
+
+Math.random() * (maximum - minimum + 1)
+
+I'm multiplying the random decimal by the size of the range.
+
+maximum - minimum + 1 ensures the range is inclusive.
+
+In this case: 100 - 1 + 1 = 100
+
+//So now you're getting a number between 0 and just under 100.
+
+Math.floor(...)
+
+//This rounds down the result to the nearest whole number.
+
+//So now you get an integer from 0 to 99.
+
++ minimum
+
+Finally, you add the minimum value (1), shifting the range from:
+
+0–99 → 1–100
+
+//Final result:
+//So, num will always be a random whole number between 1 and 100, inclusive.

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 +2,7 @@
 
 const age = 33;
 age = age + 1;
+
+let age = 33;  // Using let to declare a variable that can be reassigned
+age = age + 4;  // Now I am reassigning the value of age
+console.log(age); // This will print 37 to the console

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

@@ -1,5 +1,9 @@
 // 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";
+//The error occurs because you are trying to use the variable cityOfBirth before it is defined.
+//  In JavaScript, the line const cityOfBirth = "Bolton"; 
+// needs to run before you try to use cityOfBirth in the console.log() statement. See the corrected code below:
+
+const cityOfBirth = "Bolton";  // First, define the variable
+console.log(`I was born in ${cityOfBirth}`);  // Then, use it

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

@@ -1,9 +1,22 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = cardNumber.slice(-4); // This will throw an error
 
 // 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
+
+//SOLUTION BELOW
+
+//The code will not work because cardNumber is a number, and the .slice() method is used for strings, not numbers.
+// The .slice() method cannot be used directly on a number, which will lead to an error.
+//TypeError: cardNumber.slice is not a function.
+//This happens because .slice() is a method that only works on strings and arrays, but cardNumber is a number.
+// You can't call .slice() on a number.
+//To fix this, we need to convert the number to a string before using .slice() to extract the last 4 digits:
+
+const cardNumber = 4533787178994213;
+const last4Digits = String(cardNumber).slice(-4);  // Convert to string first
+console.log(last4Digits);  // This will output "4213"

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

@@ -1,2 +1,5 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+//CORRECTED CODE BLOW
+const twelveHourClockTime = "20:53";  // Use letters instead of starting with a number
+const twentyFourHourClockTime = "08:53";  // Use letters instead of starting with a number
+
+

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

@@ -20,3 +20,61 @@ console.log(`The percentage change is ${percentageChange}`);
 // d) Identify all the lines that are variable declarations
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+
+//There are two function calls in the file. They are:
+
+//a. carPrice.replaceAll(",", "") – This calls the replaceAll() method to remove commas from the carPrice string.
+//priceAfterOneYear.replaceAll(",", "") – This also calls the replaceAll() method to remove commas from the priceAfterOneYear string.
+
+//FULL RESPONSE BELOW:
+
+// --- CODE STARTS HERE ---
+
+let carPrice = "10,000";
+let priceAfterOneYear = "8,543";
+
+// Removing commas and converting to numbers
+carPrice = Number(carPrice.replaceAll(",", ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
+
+const priceDifference = carPrice - priceAfterOneYear;
+const percentageChange = (priceDifference / carPrice) * 100;
+
+console.log(`The percentage change is ${percentageChange}`);
+
+// --- QUESTIONS & ANSWERS ---
+
+// a) How many function calls are there in this file? Write down all the lines where a function call is made
+// Answer:
+// There are 5 function calls:
+// Line 4: carPrice.replaceAll(",", "")
+// Line 4: Number(...)
+// Line 5: priceAfterOneYear.replaceAll(",", "")
+// Line 5: Number(...)
+// Line 8: 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?
+// Answer:
+// The original error was in line 5 due to a missing comma in replaceAll.
+// Incorrect: replaceAll("," "")
+// Corrected: replaceAll(",", "")
+// The error occurred because the function call had incorrect syntax, missing a second argument.
+// Fix: Add the missing comma in replaceAll
+
+// c) Identify all the lines that are variable reassignment statements
+// Answer:
+// Line 4: carPrice is reassigned with a numeric version
+// Line 5: priceAfterOneYear is reassigned with a numeric version
+
+// d) Identify all the lines that are variable declarations
+// Answer:
+// Line 1: let carPrice = "10,000";
+// Line 2: let priceAfterOneYear = "8,543";
+// Line 6: const priceDifference = ...
+// Line 7: const percentageChange = ...
+
+// e) Describe what the expression Number(carPrice.replaceAll(",", "")) is doing - what is the purpose of this expression?
+// Answer:
+// First, carPrice.replaceAll(",", "") removes commas from the string, turning "10,000" into "10000"
+// Then, Number(...) converts the string "10000" into the number 10000
+// The purpose is to convert a formatted price string into a number so that mathematical operations can be performed.

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

@@ -23,3 +23,60 @@ console.log(result);
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+
+
+// --- CODE STARTS HERE ---
+
+const movieLength = 8784; // length of movie in seconds
+
+const remainingSeconds = movieLength % 60;
+const totalMinutes = (movieLength - remainingSeconds) / 60;
+
+const remainingMinutes = totalMinutes % 60;
+const totalHours = (totalMinutes - remainingMinutes) / 60;
+
+const result = `${totalHours}:${remainingMinutes}:${remainingSeconds}`;
+console.log(result);
+
+// --- QUESTIONS & ANSWERS ---
+
+// a) How many variable declarations are there in this program?
+// Answer:
+// There are 5 variable declarations:
+// 1. movieLength
+// 2. remainingSeconds
+// 3. totalMinutes
+// 4. remainingMinutes
+// 5. totalHours
+// 6. result
+// (So actually: **6** variable declarations using `const`)
+
+// b) How many function calls are there?
+// Answer:
+// Only 1 function call: `console.log(result);`
+
+// c) Using documentation, explain what the expression movieLength % 60 represents
+// Answer:
+// The `%` operator returns the **remainder** after division.
+// So `movieLength % 60` gives the number of **remaining seconds** after dividing the total seconds by 60.
+// In this case, it isolates the seconds that don’t fit into full minutes.
+// Reference: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators#remainder
+
+// d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// Answer:
+// `(movieLength - remainingSeconds) / 60` calculates how many **full minutes** are in the movie.
+// It first subtracts the leftover seconds, then divides by 60 to convert the rest into minutes.
+
+// e) What do you think the variable result represents? Can you think of a better name for this variable?
+// Answer:
+// `result` represents the **converted movie length in HH:MM:SS format** (hours:minutes:seconds).
+// A better name would be: `formattedTime`, `formattedDuration`, or `movieTimeFormatted` — more descriptive and readable.
+
+// f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// Answer:
+// Yes, this code will work for all **non-negative integer** values of `movieLength` (in seconds).
+// However:
+// - If movieLength is **less than 60**, it will display `0:0:seconds`
+// - It doesn’t add leading zeroes (e.g., `1:3:4` instead of `01:03:04`), so formatting could be improved for better readability.
+// - If `movieLength` is a **negative number**, it still runs but the output won't make logical sense for a duration.
+// So it works functionally, but you may want to add validation and zero-padding for a more polished version.

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

@@ -25,3 +25,87 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+
+
+
+//SOLUTIONS HERE
+
+
+// 1. const penceString = "399p": initialises a string variable with the value "399p"
+const penceString = "399p";
+
+// 2. Removes the trailing "p" by taking a substring from index 0 to the second-to-last character.
+const penceStringWithoutTrailingP = penceString.substring(
+  0,
+  penceString.length - 1
+);
+
+// 3. Pads the numeric string to ensure it's at least 3 digits (e.g., "7" becomes "007").
+// This makes it easier to extract pounds and pence.
+const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+
+// 4. Extracts the pound portion by taking all but the last two digits.
+const pounds = paddedPenceNumberString.substring(
+  0,
+  paddedPenceNumberString.length - 2
+);
+
+// 5. Extracts the pence portion by taking the last two digits and padding with "0" if needed.
+const pence = paddedPenceNumberString
+  .substring(paddedPenceNumberString.length - 2)
+  .padEnd(2, "0");
+
+// 6. Logs the formatted result in the form £x.xx
+console.log(`£${pounds}.${pence}`);
+
+// --- QUESTIONS & DETAILED RESPONSES ---
+
+// Q: What does the program do?
+// A: This program takes a price in pence as a string with a "p" suffix (e.g., "399p")
+//    and converts it to a properly formatted British pound value (e.g., £3.99).
+
+// Q: Step-by-step breakdown of what each line does?
+//
+// 1. const penceString = "399p":
+//    - Initializes the input value with a string representing the number of pence.
+//
+// 2. const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1):
+//    - Removes the trailing 'p' to isolate the numeric part (e.g., "399p" → "399").
+//
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"):
+//    - Ensures the number is at least 3 characters long by padding with zeros if necessary.
+//    - Useful for values like "7" (→ "007") to ensure valid pounds/pence splitting.
+//
+// 4. const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2):
+//    - Extracts the pound portion by slicing off the last two digits.
+//
+// 5. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"):
+//    - Extracts the pence portion (last 2 digits), padding if needed to ensure two-digit formatting.
+//
+// 6. console.log(`£${pounds}.${pence}`):
+//    - Outputs the formatted currency in pounds and pence.
+
+// Q: Will this code work for all values?
+// A: It works for most valid pence strings (like "5p", "99p", "7p", "399p"). However:
+//    - It does not validate whether the input ends with "p".
+//    - It assumes the value is in the correct format.
+//    - You could improve it by adding input validation and supporting values without "p".
+
+// --- OPTIONAL ENHANCEMENT ---
+// To convert this into a reusable function that accepts any pence string:
+function formatPenceToPounds(penceInput) {
+  if (!penceInput.endsWith("p")) {
+    return "Invalid input format";
+  }
+
+  const raw = penceInput.slice(0, -1);
+  const padded = raw.padStart(3, "0");
+  const pounds = padded.substring(0, padded.length - 2);
+  const pence = padded.substring(padded.length - 2).padEnd(2, "0");
+  return `£${pounds}.${pence}`;
+}
+
+console.log(formatPenceToPounds("5p"));      // Output: £0.05
+console.log(formatPenceToPounds("99p"));     // Output: £0.99
+console.log(formatPenceToPounds("125p"));    // Output: £1.25
+console.log(formatPenceToPounds("7"));       // Output: Invalid input format

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?
+//RESPONSE
+It says undefined
 
 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 popup a field to add my name
 What is the return value of `prompt`?
+It says undefined