digitalmars.D.learn - How to filter an array so the result is an array again?

• Cheng Wei (17/17) Sep 15 2011 The standard library std.algorithm is based on Range. So if
```The standard library std.algorithm is based on Range. So if
a = [1, 2, 3, 4];
auto r = filter!("a < 2")(a);

Here, r is a range.
How about I want an new array? Is there any easy way to convert the
result to array?

If we have to do like:
int[] b;
for (v; r) {
b ~= v;
}

Then maybe it is easier to not use filter at all as:
int [] b;
for (v; a) {
if (v < 2) b ~= v;
}

Thanks a lot.
```
Sep 15 2011
```Sorry, the 'for' should be 'foreach'.
```
Sep 15 2011    Jonathan M Davis <jmdavisProg gmx.com> writes:
```On Friday, September 16, 2011 04:04:39 Cheng Wei wrote:
The standard library std.algorithm is based on Range. So if
a = [1, 2, 3, 4];
auto r = filter!("a < 2")(a);

Here, r is a range.
How about I want an new array? Is there any easy way to convert the
result to array?

If we have to do like:
int[] b;
for (v; r) {
b ~= v;
}

Then maybe it is easier to not use filter at all as:
int [] b;
for (v; a) {
if (v < 2) b ~= v;
}

Use std.array.array.

auto a = [1, 2, 3, 4];
auto r = array(filter!"a < 2"(a));

- Jonathan M Davis
```
Sep 15 2011