How do I print # in a nested for loop

Question

 for (int i = 0; i <= 6; i++)
 {
     string[] doors = new string[6];
     doors[i] = "#";
     for (int j = 1; j <=i; j++)
         {
            Console.Write(doors[j]); 
         }
     Console.Writeline():
}

Hi guys. I need to print # one and then # twice, until i get to six times. It says System.index.out.of.range. How come?

You don't want any *array* - `string[] doors` - at all. Just print out `#` - `Console.Write('#')` — Dmitry Bychenko, Jul 02 '18 at 13:30
@Kobus: you don't want to *declare* anything. Just print out a *constant* `#` in the loops: `Console.Write('#');` — Dmitry Bychenko, Jul 02 '18 at 13:34

score 2 · Answer 1 · answered Jul 02 '18 at 13:31

You should try to extend your array, it's limited to 6 elements but you try to access 7 elements as you go through 0 to 6.

for (int i = 0; i <= 6; i++)
 {
     string[] doors = new string[7];
     doors[i] = "#";
     for (int j = 1; j <=i; j++)
         {
            Console.Write(doors[j]); 
         }
     Console.Writeline():
}

score 1 · Answer 2 · answered Jul 02 '18 at 13:33

1

because it is out of range.

change it to this:

for (int i = 0; i <= 6; i++)
 {
     string[] doors = new string[6];
     doors[i] = "#";
     for (int j = 0; j <=i.length; j++)
         {
            Console.Write(doors[j]); 
         }
     Console.Writeline():
}

answered Jul 02 '18 at 13:33

Barr J

10,636
1
28
46

What are you wanting `i.length` to do here? Given i is an `int` the answer to what it *actually* is doing is probably throwing a compiler error... – Chris Jul 02 '18 at 14:03

score 1 · Answer 3 · answered Jul 02 '18 at 13:33

1

No need to use 2 loops. Just repeat that character

for (int i = 0; i <= 6; i++)
{
  Console.Write(new String("#",i)); 
  Console.WriteLine():
}

answered Jul 02 '18 at 13:33

Adelin

7,809
5
37
65

score 1 · Accepted Answer · answered Jul 02 '18 at 13:41

If

I need to print # one and then # twice, until i get to six times.

You don't want any array - string[] doors = new string[6];, just loops:

for (int line = 1; line <= 6; ++line) {
  for (int column = 1; column <= line; ++column) {
    Console.Write('#'); 
  }

  Console.WriteLine(); 
}

If you have to work with array (i.e. array will be used somewhere else), get rid of magic numbers:

// Create and fill the array
string[] doors = new string[6];

for (int i = 0; i < doors.Length; i++) 
  doors[i] = "#";

// Printing out the array in the desired view
for (int i = 0; i < doors.Length; i++) {
  for (int j = 0; j < i; j++) {
    Console.Write(doors[j]); 
  } 

  Console.Writeline(); 
}

Please, notice that arrays are zero-based (array with 6 items has 0..5 indexes for them)

How do I print # in a nested for loop

4 Answers4