Complete Sprint 1 coursework

MouawiaElkhalifa · MouawiaElkhalifa · commit 0a4e7f6330d7 · 2026-02-16T12:39:19.000Z
diff --git a/Sprint-1/1-key-exercises/1-count.js b/Sprint-1/1-key-exercises/1-count.js
@@ -4,3 +4,9 @@ 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 reassigns the value of count.
+// The = operator assigns the result of (count + 1)
+// back to the variable count.
+// This increases the previous value of count by 1.
diff --git a/Sprint-1/1-key-exercises/2-initials.js b/Sprint-1/1-key-exercises/2-initials.js
@@ -3,9 +3,11 @@ let middleName = "Katherine";
 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.
+// 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
 
diff --git a/Sprint-1/1-key-exercises/3-paths.js b/Sprint-1/1-key-exercises/3-paths.js
@@ -17,7 +17,11 @@ 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 lastDotIndex = filePath.lastIndexOf(".");
+
+const ext = filePath.slice( lastDotIndex+1);
+
 
 // https://www.google.com/search?q=slice+mdn
diff --git a/Sprint-1/1-key-exercises/4-random.js b/Sprint-1/1-key-exercises/4-random.js
@@ -1,9 +1,38 @@
 const minimum = 1;
 const maximum = 100;
-
+// Generate a random integer between minimum and maximum (inclusive)
 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
+
+/*
+Explanation:
+
+num represents a random whole number between 1 and 100 inclusive.
+
+How it works:
+
+1. (maximum - minimum + 1)
+   Calculates how many numbers are in the range.
+   100 - 1 + 1 = 100
+
+2. Math.random()
+   Generates a decimal number such that:
+   0 ≤ value < 1
+
+3. Multiply:
+   Math.random() * 100
+   Produces a decimal between 0 and 99.999...
+
+4. Math.floor()
+   Removes the decimal part, giving an integer between 0 and 99.
+
+5. + minimum
+   Shifts the range from 0–99 to 1–100.
+6.  When running the program multiple times, num changes each time.
+   The value is always a whole number between 1 and 100.*/
diff --git a/Sprint-1/2-mandatory-errors/0.js b/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?
diff --git a/Sprint-1/2-mandatory-errors/1.js b/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;
+ 
diff --git a/Sprint-1/2-mandatory-errors/2.js b/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 ?
 
-console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);
+
diff --git a/Sprint-1/2-mandatory-errors/3.js b/Sprint-1/2-mandatory-errors/3.js
@@ -1,9 +1,28 @@
+// Original broken version
 const cardNumber = 4533787178994213;
 const last4Digits = cardNumber.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
+
+
+// Prediction:
+// The code will fail because cardNumber is a number.
+// Numbers do not have a slice() method.
+
+// After running:
+// TypeError: cardNumber.slice is not a function
+
+// Why:
+// slice() only works on strings and arrays.
+
+// Fix:
+const cardNumberString = "4533787178994213";
+const fixedLast4Digits = cardNumberString.slice(-4);
+console.log(fixedLast4Digits); // 4213
diff --git a/Sprint-1/2-mandatory-errors/4.js b/Sprint-1/2-mandatory-errors/4.js
@@ -1,2 +1,4 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const Time12HourClock = "08:53 PM";
+const Time24HourClock = "20:53";
+console.log(Time12HourClock);
+console.log(Time24HourClock);
diff --git a/Sprint-1/3-mandatory-interpret/1-percentage-change.js b/Sprint-1/3-mandatory-interpret/1-percentage-change.js
@@ -2,21 +2,40 @@ 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;
 
 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 functions calls in line 4, 5 and 10
+ //carPrice = Number(carPrice.replaceAll(",", ""));: Number(), replaceAll()
+ //priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));:Number(), replaceAll()
+ //console.log(`The percentage change is ${percentageChange}`); :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?
-
+  //The error was coming from line 5:
+  //priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+  //The error occurred because there was a missing comma between the two arguments inside the replaceAll() function.
+  //To fix the problem, we add the missing comma: priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 // 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?
+   // The expression Number(carPrice.replaceAll(",", "")) first removes all commas
+   // from the string stored in carPrice using replaceAll().
+  // For example, "10,000" becomes "10000".
+  // Then Number() converts the cleaned string into a numeric value.
+  // The purpose of this expression is to convert a formatted string price
+  // into a number so that mathematical calculations can be performed.
diff --git a/Sprint-1/3-mandatory-interpret/2-time-format.js b/Sprint-1/3-mandatory-interpret/2-time-format.js
@@ -12,14 +12,37 @@ 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.
 
 // b) How many function calls are there?
+    // There is only one function call.
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
+     // The % (modulus) operator returns the remainder after division.
+// movieLength % 60 calculates the remainder after dividing the total
+// number of seconds by 60. This gives the remaining seconds after converting the total seconds 
+// into complete minutes.
+// For example, 8784 % 60 = 24, meaning there are 24 seconds left over.
+
 // 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?
-
+   //It first subtracts the leftover seconds (remainingSeconds) to get only the seconds that form complete minutes, then divides 
+   //by 60 to convert those seconds into minutes.
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+   //  The variable result represents the movie length formatted as hours,
+   // minutes, and seconds in the format "HH:MM:SS".
+   // It combines totalHours, remainingMinutes, and remainingSeconds into
+   // a readable time string.
+   // A better variable name could be formattedTime or movieDuration,
+   // because it clearly describes that the value is a formatted time.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+    // The code works correctly for positive integers but has limitations:
+    //Works: Positive integers (e.g., 8784 → "2:26:24"), zero (0 → "0:0:0")
+    //Issues: 
+    // Negative numbers produce negative times
+    // Decimals work but give decimal seconds
+    // No zero-padding (65 seconds gives "0:1:5" instead of "0:01:05")
+    //The mathematical logic is sound for non-negative whole numbers, but the code lacks 
+    //input validation and proper time formatting with leading zeros.
diff --git a/Sprint-1/3-mandatory-interpret/3-to-pounds.js b/Sprint-1/3-mandatory-interpret/3-to-pounds.js
@@ -25,3 +25,32 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+ // 1. const penceString = "399p":
+//    Creates a string that represents a price in pence, including the trailing "p".
+
+// 2. const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1):
+//    Removes the last character ("p") from the string.
+//    Example: "399p" -> "399"
+
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"):
+//    Ensures the numeric string has at least 3 digits by adding leading zeros.
+//    This makes splitting into pounds/pence consistent.
+//    Examples: "5" -> "005", "45" -> "045", "399" -> "399"
+
+// 4. const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2):
+//    Takes everything except the last two digits.
+//    Those digits represent pence, so what remains is the pounds part.
+//    Example: "399" -> "3"  (pounds)
+
+// 5. const pence = paddedPenceNumberString
+//        .substring(paddedPenceNumberString.length - 2)
+//        .padEnd(2, "0"):
+//    Takes the last two digits (the pence part).
+//    padEnd(2, "0") ensures it is always two characters long.
+//    Example: "399" -> last two digits "99" -> stays "99"
+//    (If it were shorter, e.g. "9", it would become "90", but padStart earlier
+//     usually prevents that by making the string at least 3 digits.)
+
+// 6. console.log(`£${pounds}.${pence}`):
+//    Prints the final formatted price in pounds and pence.
+//    Example: pounds="3" and pence="99" -> "£3.99"
