2D arrays

301.17 Arrays and Records

Arrays and Records — Note 2 of 4

Table structure rows/cols.

What you need to know

A 2D array is a list of lists, representing rows and columns like a table. Access elements with two indices: grid[row][col].

What to know

A list of lists: grid = [[1,2],[3,4],[5,6]]
grid[0] is the first row
grid[0][1] is row 0, column 1
Use nested for loops to process all elements

Code examples

2D array

python

grid = [
    [1, 2, 3],
    [4, 5, 6]
]
print(grid[0][2])  # 3 (row 0, col 2)

for row in grid:
    for item in row:
        print(item, end=" ")
    print()

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Specification notes for programming are in Paper 2.