1const std = @import("std");
 2const expect = std.testing.expect;
 3const expectEqual = std.testing.expectEqual;
 4
 5const mat4x5 = [4][5]f32{
 6    [_]f32{ 1.0, 0.0, 0.0, 0.0, 0.0 },
 7    [_]f32{ 0.0, 1.0, 0.0, 1.0, 0.0 },
 8    [_]f32{ 0.0, 0.0, 1.0, 0.0, 0.0 },
 9    [_]f32{ 0.0, 0.0, 0.0, 1.0, 9.9 },
10};
11test "multidimensional arrays" {
12    // mat4x5 itself is a one-dimensional array of arrays.
13    try expectEqual(mat4x5[1], [_]f32{ 0.0, 1.0, 0.0, 1.0, 0.0 });
14
15    // Access the 2D array by indexing the outer array, and then the inner array.
16    try expect(mat4x5[3][4] == 9.9);
17
18    // Here we iterate with for loops.
19    for (mat4x5, 0..) |row, row_index| {
20        for (row, 0..) |cell, column_index| {
21            if (row_index == column_index) {
22                try expect(cell == 1.0);
23            }
24        }
25    }
26
27    // Initialize a multidimensional array to zeros.
28    const all_zero: [4][5]f32 = .{.{0} ** 5} ** 4;
29    try expect(all_zero[0][0] == 0);
30}
31
32// test