# reverse!

``````..  reverse!(v [, start=1 [, stop=length(v) ]]) -> v

In-place version of :func:`reverse`.``````

## Examples

The `reverse!(v [, start=1 [, stop=length(v) ]])` function in Julia is used to reverse the elements of a mutable collection `v` in-place. It modifies the collection `v` itself and returns it.

Here are some examples of how to use the `reverse!` function:

1. Reverse an array:

``````julia> arr = [1, 2, 3, 4, 5];
julia> reverse!(arr)
5-element Array{Int64,1}:
5
4
3
2
1``````

This example reverses the elements of the array `arr` in-place.

2. Reverse a subset of an array:

``````julia> arr = [1, 2, 3, 4, 5];
julia> reverse!(arr, 2, 4)
5-element Array{Int64,1}:
1
4
3
2
5``````

Here, the function reverses the elements from index 2 to index 4 (inclusive) in the array `arr`.

3. Reverse a string:
``````julia> str = "Hello, Julia!";
julia> reverse!(str)
"!ailuJ ,olleH"``````

The `reverse!` function can also be used to reverse the characters in a string in-place.

It's important to note that the `reverse!` function modifies the original collection directly. If you want to create a new reversed collection without modifying the original one, you can use the `reverse` function instead.

Please let me know if you need any further assistance!