WEST MIDLANDS | JAN_2025 | IFEANYI MADUBUGWU | MODULE STRUCTUING AND STORING DATA | SPRINT 1

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

@@ -4,3 +4,6 @@ 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
+
+//Answer:
+// Line 3 is an expression which calculate the current value of count and also add 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[0] + middleName[0] + lastName[0];
+console.log(initials);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 

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

@@ -12,12 +12,22 @@
 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 = ;
+const dir = filePath.slice(0, lastSlashIndex);
+const ext = base.slice(base.lastIndexOf("."));
+
+console.log(`${dir}`);
+console.log(`${ext}`);
+console.log(`The base part of ${filePath} is ${base}`);
+
+
+
+
+
+
 
 // https://www.google.com/search?q=slice+mdn

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

@@ -7,3 +7,6 @@ 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
+
+// Answer:
+// The variable num represents a randomly generated whole number between 1 and 100 (inclusive).Since minimum is 1 and maximum is 100, we generate a random number within this range using Math.random(). This function produces a decimal between 0 and 1, which we scale to the desired range.Math.floor() rounds the result down to the nearest whole number, ensuring we get an integer.Each time the code runs, num will hold a different random integer between 1 and 100.

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 +1,7 @@
 // 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 +1,11 @@
 // 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";
+
+// Answer:
+// i noticed on this syntax you tried to evaluate a variable before it was declare. that was why we got an error message.
+//below is the correct syntax:
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);

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

@@ -1,9 +1,17 @@
+// const cardNumber = 4533787178994213;
+// const last4Digits = cardNumber.slice(-4);
+
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = cardNumber.toString().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
+
+//Answer:
+//After running the code, I noticed that cardNumber.slice is not a function. This happens because .slice() method only works on strings, not numbers. To fix this, we need to convert the number to a string using .toString(). Please refer to the corrected code above.

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

@@ -1,2 +1,13 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const hour24ClockTime1 = "20:53";
+const hour24ClockTime2 = "08:53";
+
+function convertTo12Hours(time24) {
+    let [hours, minutes] = time24.split(":");
+    let period = hours >= 12 ? "PM" : "AM";
+    hours = hours % 12 || 12; 
+    return hours + ":" + minutes + " " + period;
+
+}
+
+console.log(convertTo12Hours("20:53"));
+console.log(convertTo12Hours("08:53"));

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

@@ -1,8 +1,8 @@
 let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
-carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+carPrice = Number(carPrice.replaceAll("," , ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," , ""));
 
 const priceDifference = carPrice - priceAfterOneYear;
 const percentageChange = (priceDifference / carPrice) * 100;
@@ -12,11 +12,16 @@ 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
+// Answer: We have 5 function calls. Number(),replaceAll(),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 error is on Line 5 because replaceAll("," "") is incorrectly written. The correct syntax is replaceAll(",", "").
 
 // c) Identify all the lines that are variable reassignment statements
+// Answer: Line 4 and 5 are variable reassign statement.
 
 // d) Identify all the lines that are variable declarations
+// Answer: Line 1,2, 7 and 8 are variable declaration.
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// Answer: we need to remove comma from  this expression Number(carPrice.replaceAll(",","")) to allow us convert number to string using .string() method. this allows mathematical expression to work correctly in java.

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

@@ -12,14 +12,21 @@ 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?
+// Answer: there is only 5 variable declaration.
 
 // b) How many function calls are there?
+// Answer: only one function call console.log()
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// Answer: Movie length calculate the remaining seconds after dividing by 60
+8784 % 60 = 146, leaving reminder of 24.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// Answer: totalMinutes we remove movieLength and remainingSeconds and then divide by 60.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+//Answer: this represent a format time string
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// this code works, but it does not work for negative value or decimal function.

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

@@ -1,21 +1,25 @@
 const penceString = "399p";
+// this p at the end of 399p represent pence
 
-const penceStringWithoutTrailingP = penceString.substring(
-  0,
-  penceString.length - 1
-);
+const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1);
+// // this remove the letter p from the variable penceString. which means start from the first letter 0 and stop one character before the end. 
 
 const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
-const pounds = paddedPenceNumberString.substring(
-  0,
-  paddedPenceNumberString.length - 2
-);
+// This makes sure the string is at least 3 digits long by adding "0" at the start if needed.
 
-const pence = paddedPenceNumberString
-  .substring(paddedPenceNumberString.length - 2)
-  .padEnd(2, "0");
+const penceNumber = parseInt(paddedPenceNumberString, 10);
+//  Converts the string to a number to avoid issues.
+
+const pounds = Math.floor(penceNumber / 100); 
+// get the whole pound
+
+const pence = (penceNumber % 100).toString().padStart(2, "0"); 
+// this code takes the last two digits for the pence part.
 
 console.log(`£${pounds}.${pence}`);
+// this evaluate the final price in pence and pound format 
+
+
 
 // This program takes a string representing a price in pence
 // The program then builds up a string representing the price in pounds
@@ -25,3 +29,5 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+
+

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?
+// After calling the alert function with "Hello World!", I notice a pop-up on my screen displaying 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?
+// After invoking the prompt function and storing its return value in the variable myName, I notice a pop-up on my screen with a text input field asking, "What is your name?".
+
 What is the return value of `prompt`?
+// The return value is whatever the user types in the input field. If the user clicks Cancel, the return value is null

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

@@ -5,12 +5,21 @@ 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?
+// After entering console.log, I notice a new code output ƒ log() { [native code] }.
 
 Now enter just `console` in the Console, what output do you get back?
 
+// After calling console, I notice a dropdown appears, showing the console object with various functions {debug: ƒ, error: ƒ, info: ƒ, log: ƒ, warn: ƒ, …}
+
 Try also entering `typeof console`
+// i notice a return called objective which confirms that console is an object in JavaScript.
 
 Answer the following questions:
 
 What does `console` store?
+// console is an object provided by the browser that stores logging and debugging methods like log(), error(), warn(),
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+// console is an objective, while .log is a method(function) inside the objective console.
+// the `.` is a property access in javascript.
+console.log() means access the log method from the console and use it for the objective.