What is the simplest way to output every nth element of an array?

I can do it using a for loop:
void main()
{
    int[5] a = [1,2,3,4,5];

    for (int i = 0 ; i <= 4 ; i += 2)
    {
        writeln(a[i]);
    }
}

Basically, I am wondering if I missed something.

There are two other way:
```D
import std;

void main()
{
    int[] a = [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 ];

    // using foreach
    foreach (i; 0..a.length)
        write(a[i], ", ");
    writeln;

    // using stride
    writeln(stride(a, 2));
}
```

On Wednesday, 21 October 2020 at 12:06:00 UTC, drug wrote:
> There are two other way:

Thanks, drug.

stride was what I was looking for.

On Wednesday, 21 October 2020 at 11:55:54 UTC, DMon wrote:
> What is the simplest way to output every nth element of an array?
>
> I can do it using a for loop:
> void main()
> {
>     int[5] a = [1,2,3,4,5];
>
>     for (int i = 0 ; i <= 4 ; i += 2)
>     {
>         writeln(a[i]);
>     }
> }
>
> Basically, I am wondering if I missed something.

In addition to the drug's solution, this reminds me of the chunks of std.range.

import std.range;
import std.stdio;

void main(){
    auto source = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
    auto chunks = chunks(source, 2);

    writeln(chunks[0]); // [1, 2]

    foreach(c; chunks)
    	writeln(c[1]);
}

output:
2
4
6
8
10

On Wednesday, 21 October 2020 at 12:06:00 UTC, drug wrote:
> There are two other way:
> ...
>     // using foreach
>     foreach (i; 0..a.length)
>         write(a[i], ", ");
> ...

Yes you can use foreach, but in this case will not act the way the OP wanted. In his for loop example the "i" is incremented by 2: "i+=2".

So to perform what OP want with foreach it should be:

    foreach (i,j;a){
        if(i%2==0){ write(j, ", ");}
    }

By the way it's possible to set a "step" value for "foreach"?

Matheus.

On Wednesday, 21 October 2020 at 13:43:51 UTC, matheus wrote:
>     foreach (i,j;a){
>         if(i%2==0){ write(j, ", ");}
>     }

Thank you, matheus. for each on the list.

On Wednesday, 21 October 2020 at 13:04:40 UTC, Ferhat Kurtulmuş wrote:
> import std.range;
> import std.stdio;
>
> void main(){
>     auto source = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
>     auto chunks = chunks(source, 2);
>
>     writeln(chunks[0]); // [1, 2]
>
>     foreach(c; chunks)
>     	writeln(c[1]);
> }

And, thank you Kurtulmuṣ (that's the closest "s" this keyboard has).

I've played with std.range but didn't think a control structure or import should be necessary.

On Wednesday, 21 October 2020 at 14:03:54 UTC, DMon wrote:
> On Wednesday, 21 October 2020 at 13:04:40 UTC, Ferhat Kurtulmuş wrote:
>> import std.range;
>> import std.stdio;
>>
>> void main(){
>>     auto source = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
>>     auto chunks = chunks(source, 2);
>>
>>     writeln(chunks[0]); // [1, 2]
>>
>>     foreach(c; chunks)
>>     	writeln(c[1]);
>> }
>
> And, thank you Kurtulmuṣ (that's the closest "s" this keyboard has).
>
> I've played with std.range but didn't think a control structure or import should be necessary.

:) 'sh' sound in English

ş

UTF-8: Å&#376
Numeric: ş
Ansi: ÅŸ

On Wednesday, 21 October 2020 at 16:38:34 UTC, Ferhat Kurtulmuş wrote:
> ş
>
> UTF-8: Å&#376
> Numeric: ş
> Ansi: ÅŸ

√