C#•15mo ago

❔ Iterate over a range

What's the equivalent of this (rust)

for i in 0..10 { /* ...do stuff... */ }

for i in 0..10 { /* ...do stuff... */ }

in C#? So basically, how to loop over a range? I'm not a big fan of C-style loops 😄 I find them very noisy and cumbersome.

14 Replies

__dil__OP•15mo ago

Oh thanks! I'm really starting out so I didn't know about extension but that does make sense. It's not a big deal, but I highly doubt I'd ever need ranges from the end of int. Is there any way I could specialize this so it doesn't do the branching stuff to account for IsFromEnd? that would still require branching though (i.e. some form of conditional to check IsFromEnd) I thought there might be a specialized type for ranges whose bounds are only from the start (not IsFromEnd) but I might just be wishful 🙂

Angius•15mo ago

You could use Enumerable.Range() too

foreach (var i in Enumerable.Range(0, 10))
{
    // 0 to 9
}

foreach (var i in Enumerable.Range(0, 10))
{
    // 0 to 9
}

__dil__OP•15mo ago

A bit less ergonomic, but yeah that works 🙂 thanks to both of you

Angius•15mo ago

using static System.Linq.Enumerable;

foreach (var i in Range(0, 10))
{
    // 0 to 9
}

using static System.Linq.Enumerable;

foreach (var i in Range(0, 10))
{
    // 0 to 9
}

will make it a little more ergonomic

__dil__OP•15mo ago

hmmm yeah that could be a good solution Obviously I'm pretty new to C# so, is this concept of iterating over a range common/accepted in this language? I feel like the fact that this isn't built-in might mean that I'm going against the grain here

Angius•15mo ago

Well, ranges are quite a new thing (by ranges I mean the x..y syntax) and they don't really represent a "from-to" in a numeric sense. After all, what does ^7.., or "from seventh from the end, to the end" mean in terms of numbers? int.MaxValue - 7 to int.MaxValue? inf - 7 to inf? You usually see regular for loops if you really need the index Most commonly, though, you just... don't need the index

__dil__OP•15mo ago

yeah sure, I imagine with most collections I'd just use foreach and it'd work out-of-the-box, but for algorithms it's not rare to need either the index, or a (index, item) pair

Angius•15mo ago

Can't say I see much that would require an index Besides maybe some sort of a parser where you might have to look up i + 2 item ahead or something

__dil__OP•15mo ago

well, just as an example, sorting algorithms are usually expressed using indexes doesn't really matter though, I do agree that it's not a common thing

Angius•15mo ago

.Sort()

__dil__OP•15mo ago

yeah yeah, I'm just messing around to get a feel for the language :p In any case, there's more than one way to sort a collection depending on the performance characteristics that you seek. But I digress, performance is not a concern here, ultimately I was just curious.

Angius•15mo ago

So, yeah, to sum it up: most commonly you use a foreach or LINQ, on the rare cases you need an index you use a classic for loop

__dil__OP•15mo ago

alright, thanks 🙂

Accord•15mo ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

Gaming

Programming

❔ Iterate over a range