Logo

Programming-Idioms

# 264 Automated passing of array bounds
Pass a two-dimensional integer array a to a procedure foo and print the size of the array in each dimension. Do not pass the bounds manually. Call the procedure with a two-dimensional array.
New implementation

Be concise.

Be useful.

All contributions dictatorially edited by webmasters to match personal tastes.

Please do not paste any copyright violating material.

Please try to avoid dependencies to third-party libraries and frameworks.

Other implementations 
foo(List<List<int>> a) => print("${a.length} ${a[0].length}");
var a = [
    [1, 2],
    [3, 4],
    [5, 6]
  ];
foo(a);
module x
contains
  subroutine foo(a)
    integer, dimension(:,:) :: a
    print *,size(a,1), size(a,2)
  end subroutine foo
end module x

program main
  use x
  integer, dimension(5,10) :: a
  call foo(a)
end program main
foo :: [[a]] -> IO ()
foo a = print (length a, length $ head a)

main :: IO ()
main = foo [[1, 2, 3], [4, 5, 6]]
type
  T2DArray = array of array of Integer;

procedure foo(A: T2DArray);
begin
  writeln(Length(A),', ', Length(A[0]));
end;

var A: T2DArray;

begin
  A := T2DArray.Create([1,2,3],[1,2,3]);
  foo(A);  //prints 2, 3
end.
sub foo {
    my ($a) = @_;
    return scalar @{ $a }, scalar @{ $a->[0] };
}

my $a = [[1,2,3], [4,5,6]];
printf "%d %d\n", foo($a);

def foo(a):
    print(len(a), len(a[0]))
    return


a = [[1,2,3], [4,5,6]]
foo(a)

def foo(ar)
  puts "#{ar.size} #{ar.first.size}"
end

a = [[1,2,3], [4,5,6]]
foo(a)
fn foo(matrix: &[Vec<i32>]) {
    let iter = matrix.iter();
    let (vertical, _) = iter.size_hint();
    let horizontal = iter
        .max()
        .expect("empty array!")
        .len();
    println!("{horizontal} by {vertical}");
}

fn main() {
    let matrix = vec![
        vec![1, 2, 3],
        vec![4, 5, 6],
    ];
    foo(&matrix);
}
fn foo<const X: usize, const Y: usize>(_: [[i32;X];Y]) {
    println!("{} {}", Y, X);
}

let a = [
    [1, 2, 3],
    [4, 5, 6],
];
foo(a);

Preview