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+// ============================================================
+//   JavaScript Data Types Lab — lab.js
+//   Covers: Strings, Numbers, Arrays, Objects + Final Challenge
+// ============================================================
+
+
+// ============================================================
+// PART 1: STRINGS
+// ============================================================
+
+console.log("==============================");
+console.log("  PART 1: STRINGS");
+console.log("==============================");
+
+// --- Practice 1: String Manipulation ---
+
+let fullName = "Marcus Brown";
+
+// Task 1 – Print the length of the string
+console.log("Full name:", fullName);
+console.log("Length of fullName:", fullName.length);
+// .length returns the total number of characters in the string (including spaces)
+
+// Task 2 – Convert to uppercase
+console.log("Uppercase:", fullName.toUpperCase());
+
+// Task 3 – Check if it includes the last name
+console.log("Includes 'Brown'?", fullName.includes("Brown"));
+// .includes() returns true or false depending on whether the substring is found
+
+// Task 4 – Slice out the first name only
+//           "Marcus Brown" → first name starts at index 0, ends before the space at index 6
+let firstName = fullName.slice(0, 6);
+console.log("First name only:", firstName);
+// .slice(start, end) extracts characters from index start up to (but not including) index end
+
+// --- Mini Challenge 1 ---
+// Function that accepts a name and returns "Hello, NAME!" (name in all caps)
+
+function greetUser(name) {
+  return "Hello, " + name.toUpperCase() + "!";
+}
+
+console.log("\n-- Mini Challenge 1 --");
+console.log(greetUser("Marcus"));
+console.log(greetUser("coreye"));
+
+// --- Check for Understanding (Part 1) ---
+/*
+  1. What does .length do?
+     → .length returns the number of characters in a string (or the number of
+       elements in an array). It counts every character, including spaces.
+
+  2. What does .includes() return?
+     → .includes() returns a boolean: true if the given substring exists anywhere
+       inside the string, false if it does not.
+
+  3. What does .slice() do?
+     → .slice(start, end) extracts and returns a portion of the string starting
+       at the 'start' index and ending just before the 'end' index, without
+       modifying the original string.
+*/
+
+
+// ============================================================
+// PART 2: NUMBERS
+// ============================================================
+
+console.log("\n==============================");
+console.log("  PART 2: NUMBERS");
+console.log("==============================");
+
+// --- Practice 2: Number Logic ---
+
+let num1 = 10;
+let num2 = 3;
+
+// Task 1 – Basic arithmetic
+console.log("num1 =", num1, "| num2 =", num2);
+console.log("Addition      (num1 + num2):", num1 + num2);
+console.log("Subtraction   (num1 - num2):", num1 - num2);
+console.log("Multiplication(num1 * num2):", num1 * num2);
+console.log("Division      (num1 / num2):", num1 / num2);
+
+// Task 2 – Find the remainder (modulo)
+console.log("Remainder     (num1 % num2):", num1 % num2);
+// % (modulo) returns what is left over after integer division — e.g., 10 / 3 = 3 remainder 1
+
+// Task 3 – Round a decimal number
+let decimal = 7.46;
+console.log("\nDecimal value:", decimal);
+console.log("Math.round(7.46):", Math.round(decimal));  // rounds to nearest integer → 7
+console.log("Math.floor(7.46):", Math.floor(decimal));  // always rounds DOWN          → 7
+console.log("Math.ceil(7.46) :", Math.ceil(decimal));   // always rounds UP            → 8
+
+// Task 4 – Generate a random number between 1 and 10 (inclusive)
+let randomNum = Math.floor(Math.random() * 10) + 1;
+console.log("Random number (1–10):", randomNum);
+// Math.random() produces a float in [0, 1).
+// Multiply by 10 → [0, 10), floor → [0, 9], then +1 → [1, 10].
+
+// --- Mini Challenge 2 ---
+// Function that accepts a number and returns "Even" or "Odd"
+
+function evenOrOdd(number) {
+  if (number % 2 === 0) {
+    return "Even";
+  } else {
+    return "Odd";
+  }
+}
+
+console.log("\n-- Mini Challenge 2 --");
+console.log("4 is:", evenOrOdd(4));
+console.log("7 is:", evenOrOdd(7));
+console.log("0 is:", evenOrOdd(0));
+console.log("13 is:", evenOrOdd(13));
+
+// --- Check for Understanding (Part 2) ---
+/*
+  1. What does % do?
+     → The modulo operator (%) returns the remainder of a division. For example,
+       10 % 3 = 1 because 10 divided by 3 is 3 with a remainder of 1. It is
+       commonly used to test whether a number is even (n % 2 === 0) or to
+       cycle through a range of values.
+
+  2. What does Math.random() return?
+     → Math.random() returns a pseudo-random floating-point number between 0
+       (inclusive) and 1 (exclusive). To get a range such as 1–10, you scale
+       and shift the result: Math.floor(Math.random() * 10) + 1.
+
+  3. When would you use Math.floor()?
+     → Math.floor() is used when you need the largest integer less than or equal
+       to a given number — i.e., when you always want to round down. It is
+       particularly useful when generating random integers from Math.random(),
+       working with array indices, or converting floats to whole units (e.g.,
+       converting seconds to whole minutes without going over).
+*/
+
+
+// ============================================================
+// PART 3: ARRAYS
+// ============================================================
+
+console.log("\n==============================");
+console.log("  PART 3: ARRAYS");
+console.log("==============================");
+
+// --- Practice 3: Array Work ---
+
+let students = ["Alice", "Bob", "Charlie", "Diana"];
+
+// Task 1 – Print all students
+console.log("Initial students array:", students);
+console.log("Printing each student with a loop:");
+for (let i = 0; i < students.length; i++) {
+  console.log("  Student[" + i + "]:", students[i]);
+}
+
+// Task 2 – Add a new student
+students.push("Edward");
+console.log("\nAfter push('Edward'):", students);
+
+// Task 3 – Remove the last student
+let removed = students.pop();
+console.log("Removed student (pop):", removed);
+console.log("After pop:", students);
+
+// Task 4 – Print total number of students
+console.log("Total number of students:", students.length);
+
+// --- Mini Challenge 3 ---
+// Function that accepts an array of numbers and returns their sum
+
+function sumArray(numbers) {
+  let total = 0;
+  for (let i = 0; i < numbers.length; i++) {
+    total += numbers[i];
+  }
+  return total;
+}
+
+console.log("\n-- Mini Challenge 3 --");
+console.log("Sum of [1, 2, 3, 4, 5]:", sumArray([1, 2, 3, 4, 5]));
+console.log("Sum of [10, 20, 30]:", sumArray([10, 20, 30]));
+console.log("Sum of [7, 14, 3, 9]:", sumArray([7, 14, 3, 9]));
+
+// --- Check for Understanding (Part 3) ---
+/*
+  1. How do you access an array element?
+     → By its zero-based index inside square brackets: arrayName[index].
+       For example, students[0] returns the first element, students[2] returns
+       the third, and so on.
+
+  2. What does .push() do?
+     → .push(value) adds one or more elements to the END of an array and returns
+       the new length of the array. The original array is modified in place.
+
+  3. Why do we use loops with arrays?
+     → Because arrays can hold many elements. A loop lets us visit each element
+       automatically without having to write separate console.log or processing
+       statements for every index. It also makes the code work correctly
+       regardless of how many items are in the array.
+*/
+
+
+// ============================================================
+// PART 4: OBJECTS
+// ============================================================
+
+console.log("\n==============================");
+console.log("  PART 4: OBJECTS");
+console.log("==============================");
+
+// --- Practice 4: Object Work ---
+
+let car = {
+  brand: "Toyota",
+  model: "Camry",
+  year: 2020
+};
+
+// Task 1 – Print each property
+console.log("Car object:", car);
+console.log("Brand:", car.brand);
+console.log("Model:", car.model);
+console.log("Year:", car.year);
+
+// Task 2 – Update the year
+car.year = 2024;
+console.log("\nUpdated year to 2024:", car.year);
+
+// Task 3 – Add a new property (color)
+car.color = "Midnight Blue";
+console.log("Added color property:", car.color);
+console.log("Car after updates:", car);
+
+// Task 4 – Loop through the object
+console.log("\nLooping through car object:");
+for (let key in car) {
+  console.log("  " + key + ":", car[key]);
+}
+
+// --- Mini Challenge 4 ---
+// Function that accepts a person object and returns "Name is AGE years old"
+
+function describePersona(person) {
+  return person.name + " is " + person.age + " years old.";
+}
+
+console.log("\n-- Mini Challenge 4 --");
+let person1 = { name: "Coreye", age: 25 };
+let person2 = { name: "Jordan", age: 30 };
+console.log(describePersona(person1));
+console.log(describePersona(person2));
+
+// --- Check for Understanding (Part 4) ---
+/*
+  1. What is a key-value pair?
+     → A key-value pair is the fundamental unit of an object. The key is a
+       string label (like "name" or "age") and the value is the data associated
+       with that label (like "Marcus" or 25). Together they look like:
+       { key: value }.
+
+  2. How do you access object data?
+     → Two ways:
+       • Dot notation:    object.propertyName   (e.g., car.brand)
+       • Bracket notation: object["propertyName"] (e.g., car["brand"])
+       Bracket notation is required when the key is stored in a variable or
+       contains special characters.
+
+  3. When would you use an object instead of an array?
+     → Use an object when data has named properties and the order doesn't
+       matter — for example, a user profile with name, email, and age.
+       Use an array when you have an ordered list of similar items — for
+       example, a list of student names or scores — especially when you need
+       to iterate over them by index.
+*/
+
+
+// ============================================================
+// FINAL CHALLENGE: STUDENT PROFILE SYSTEM
+// ============================================================
+
+console.log("\n==============================");
+console.log("  FINAL CHALLENGE");
+console.log("  Student Profile System");
+console.log("==============================");
+
+// --- Step 1: Student Objects ---
+
+let student1 = {
+  name: "John",
+  scores: [80, 90, 75, 100]
+};
+
+let student2 = {
+  name: "Aaliyah",
+  scores: [55, 60, 72, 58]
+};
+
+let student3 = {
+  name: "Marcus",
+  scores: [95, 88, 92, 97]
+};
+
+// --- Step 2: Helper function — calculate average score ---
+// Accepts an array of scores, loops through them, and returns the average.
+
+function calculateAverage(scoresArray) {
+  let total = 0;
+  for (let i = 0; i < scoresArray.length; i++) {
+    total += scoresArray[i];   // accumulate each score
+  }
+  return Math.round(total / scoresArray.length); // round to whole number
+}
+
+// --- Step 3: Helper function — determine letter grade from average ---
+
+function getGrade(average) {
+  if (average >= 90) {
+    return "A";
+  } else if (average >= 80) {
+    return "B";
+  } else if (average >= 70) {
+    return "C";
+  } else if (average >= 60) {
+    return "D";
+  } else {
+    return "F";
+  }
+}
+
+// --- Step 4: Main function — print student report ---
+// Accepts a student object, calculates average and grade, and prints a report.
+
+function printStudentReport(student) {
+  let average = calculateAverage(student.scores);
+  let grade   = getGrade(average);
+
+  console.log("------------------------------");
+  console.log("Name:    " + student.name);
+  console.log("Scores:  " + student.scores.join(", "));
+  console.log("Average: " + average);
+  console.log("Grade:   " + grade);
+}
+
+// --- Run Reports ---
+
+printStudentReport(student1);
+printStudentReport(student2);
+printStudentReport(student3);
+
+console.log("------------------------------");
+
+
+// ============================================================
+// REFLECTION
+// ============================================================
+
+/*
+  1. Which data type felt easiest?
+     → Strings felt the easiest. The built-in methods (.length, .toUpperCase,
+       .includes, .slice) have very readable names that make it obvious what
+       they do. Experimenting with them required very little setup — just
+       declare a string variable and call a method.
+
+  2. Which one was most confusing?
+     → Objects were the most confusing at first. Unlike arrays where every
+       item is accessed by a simple numeric index, objects use named keys,
+       and there are two different syntaxes for accessing them (dot notation
+       vs. bracket notation). Looping over an object with "for...in" also
+       felt less intuitive than looping over an array with a standard for loop.
+
+  3. How do arrays and objects differ?
+     → Arrays are ordered, indexed collections of values where each item is
+       accessed by its numeric position (index 0, 1, 2, …). They are best
+       for storing lists of similar things.
+       Objects are unordered collections of key-value pairs where each value
+       is accessed by a descriptive string key (e.g., person.name). They are
+       best for storing a single entity that has multiple named attributes.
+
+  4. When would you use each in real applications?
+     → Arrays:
+         • A shopping cart (list of product objects)
+         • A leaderboard (list of scores)
+         • A to-do list (list of task strings)
+         • Any time you need to iterate over many similar items
+
+       Objects:
+         • A user profile (name, email, age, address)
+         • A product listing (title, price, description, inStock)
+         • Configuration settings (apiUrl, timeout, retries)
+         • Any time you need to group related but differently-named pieces
+           of data about one "thing"
+
+       In real applications you almost always use them together:
+       an array of objects is the standard way to represent a collection
+       of records — for example, an array of student objects where each
+       object has a name and a scores array (exactly what we built in
+       the Final Challenge!).
+*/