select!

select!(v, k, [by=,] [lt=,] [rev=false])

Partially sort the vector v in place, according to the order specified by by, lt and rev so that the value at index k (or range of adjacent values if k is a range) occurs at the position where it would appear if the array were fully sorted via a non-stable algorithm. If k is a single index, that value is returned; if k is a range, an array of values at those indices is returned. Note that select! does not fully sort the input array.

Examples

Select the k-th smallest element in an array:
```
julia> arr = [10, 5, 8, 3, 2, 6];
julia> select!(arr, 3)
6
```
This example selects the 3rd smallest element from the array arr. The array arr will be partially sorted, and the value 6 is returned.
Select a range of elements from an array:
```
julia> arr = [7, 2, 9, 4, 1, 6];
julia> select!(arr, 2:4)
3-element Array{Int64,1}:
2
4
6
```
It selects a range of elements from index 2 to 4 in the array arr. The array arr will be partially sorted, and an array of values [2, 4, 6] is returned.
Sort array in descending order:
```
julia> arr = [5, 2, 8, 1, 9, 3];
julia> select!(arr, 1, rev=true)
9
```
It partially sorts the array arr in descending order and selects the largest value. The value 9 is returned.

Common mistake example:

julia> arr = [3, 7, 1];
julia> select!(arr, 4)
ERROR: BoundsError: attempt to access 3-element Array{Int64,1} at index [4]

In this example, the index provided is out of bounds for the array. Ensure that the index or range passed to select! is within the valid range of the vector v.

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select!

Examples

See Also

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