Two-dimensional arrays in Java - Mini Project: Build & Apply

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Working with Two-Dimensional Arrays in Java

📖 Scenario: You are organizing a small seating chart for a classroom. The classroom has 3 rows and 4 columns of seats. Each seat can hold the name of one student.

🎯 Goal: You will create a two-dimensional array to store student names, set up a helper variable for the number of rows, fill the array with student names, and finally print the seating chart.

📋 What You'll Learn

Create a two-dimensional array of strings called seatingChart with 3 rows and 4 columns.

Create an integer variable called rows and set it to 3.

Fill the seatingChart array with the exact student names provided.

Use nested for loops with variables i and j to print each student's name in the seating chart.

💡 Why This Matters

🌍 Real World

Two-dimensional arrays are useful for storing grid-like data such as seating charts, game boards, or tables.

💼 Career

Understanding two-dimensional arrays is important for software development roles that involve data organization, UI layouts, or matrix computations.

1

Create the two-dimensional array

Create a two-dimensional array of strings called seatingChart with 3 rows and 4 columns.

Java

// Your code here

💡 Need a hint?

Use new String[3][4] to create the array with 3 rows and 4 columns.

2

Add a variable for the number of rows

Add an integer variable called rows and set it to 3.

Java

public class Seating {
    public static void main(String[] args) {
        String[][] seatingChart = new String[3][4];
        // Your code here
    }
}

💡 Need a hint?

Declare int rows = 3; to store the number of rows.

3

Fill the seating chart with student names

Fill the seatingChart array with these exact student names in order by row and column:
"Alice", "Bob", "Charlie", "Diana" in row 0,
"Ethan", "Fiona", "George", "Hannah" in row 1,
and "Ian", "Jane", "Kyle", "Laura" in row 2.

Java

public class Seating {
    public static void main(String[] args) {
        String[][] seatingChart = new String[3][4];
        int rows = 3;
        // Your code here
    }
}

💡 Need a hint?

Assign each student name to the correct position using seatingChart[row][column] = "Name";.

4

Print the seating chart

Use nested for loops with variables i and j to print each student's name from seatingChart. Print each row on a new line with names separated by spaces.

Java

public class Seating {
    public static void main(String[] args) {
        String[][] seatingChart = new String[3][4];
        int rows = 3;
        seatingChart[0][0] = "Alice";
        seatingChart[0][1] = "Bob";
        seatingChart[0][2] = "Charlie";
        seatingChart[0][3] = "Diana";
        seatingChart[1][0] = "Ethan";
        seatingChart[1][1] = "Fiona";
        seatingChart[1][2] = "George";
        seatingChart[1][3] = "Hannah";
        seatingChart[2][0] = "Ian";
        seatingChart[2][1] = "Jane";
        seatingChart[2][2] = "Kyle";
        seatingChart[2][3] = "Laura";
        // Your code here
    }
}

💡 Need a hint?

Use for (int i = 0; i < rows; i++) and inside it for (int j = 0; j < seatingChart[i].length; j++) to print names with System.out.print and a space. Use System.out.println() after each row.