Codehs 8.1.5 Manipulating 2d Arrays May 2026

The Gridkeeper’s Apprentice

Elara never wanted to be a Gridkeeper. She wanted to paint nebulas, not debug the rigid, glowing lattice that powered the city of Veridian. But when the old Keeper, Master Thorne, caught her secretly feeding corrupted data into the city’s light fountains, he didn’t exile her. He made her his apprentice.

# Assume 'grid' is already defined or you are creating one # Example: Creating a 3x3 grid filled with zeros grid = [[0, 0, 0], [0, 0, 0], [0, 0, 0]] # Manipulating the array for row in range(len(grid)): for col in range(len(grid[row])): # Logic to change values # Example: set each element to the sum of its indices grid[row][col] = row + col # Printing the result to verify for row in grid: print(row) Use code with caution. Copied to clipboard Common Tasks in this Lesson Codehs 8.1.5 Manipulating 2d Arrays

Manipulating 2D Arrays in CodeHS: A Comprehensive Guide The Gridkeeper’s Apprentice Elara never wanted to be

arrayName[rowIndex][columnIndex] = newValue;

Getting Dimensions

• Number of rows: matrix.length
• Number of columns in row 0: matrix[0].length

Adding and Removing Rows and Columns

• Adding a Row: You can add a new row to the end of a 2D array using the push() method.
• Removing a Row: You can remove the last row from a 2D array using the pop() method.
• Adding a Column: You can add a new column to a 2D array by iterating over each row and adding a new element to the end of the row.
• Removing a Column: You can remove a column from a 2D array by iterating over each row and removing the last element.