zig/doc/langref/test_multidimensional_arrays.zig
Andrew Barchuk 0d65b014ea
Clarify the multidimensional array example
Use a rectangular matrix instead of a square one to distinguish rows and
columns more clearly. Extend the example with row access.
2025-03-26 15:41:14 +01:00

32 lines
969 B
Zig

const std = @import("std");
const expect = std.testing.expect;
const expectEqual = std.testing.expectEqual;
const mat4x5 = [4][5]f32{
[_]f32{ 1.0, 0.0, 0.0, 0.0, 0.0 },
[_]f32{ 0.0, 1.0, 0.0, 1.0, 0.0 },
[_]f32{ 0.0, 0.0, 1.0, 0.0, 0.0 },
[_]f32{ 0.0, 0.0, 0.0, 1.0, 9.9 },
};
test "multidimensional arrays" {
// mat4x5 itself is a one-dimensional array of arrays.
try expectEqual(mat4x5[1], [_]f32{ 0.0, 1.0, 0.0, 1.0, 0.0 });
// Access the 2D array by indexing the outer array, and then the inner array.
try expect(mat4x5[3][4] == 9.9);
// Here we iterate with for loops.
for (mat4x5, 0..) |row, row_index| {
for (row, 0..) |cell, column_index| {
if (row_index == column_index) {
try expect(cell == 1.0);
}
}
}
// Initialize a multidimensional array to zeros.
const all_zero: [4][5]f32 = .{.{0} ** 5} ** 4;
try expect(all_zero[0][0] == 0);
}
// test