> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/sidef-lang/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/sidef-lang/programming_tasks/f/four_sides_of_square.md).

# Four sides of square

```ruby
var n = 5
 
[n.of(1), (n-2).of([1, (n-2).of(0)..., 1])..., n.of(1)].each {|row|
    say row.join(' ')
}
```

#### Output:

```
1 1 1 1 1
1 0 0 0 1
1 0 0 0 1
1 0 0 0 1
1 1 1 1 1
```