first

..  first(coll)

Get the first element of an iterable collection. Returns the start point of a :obj:`Range`
even if it is empty.

Examples

julia> foo = [1 2 3; 4 5 6]
2x3 Array{Int64,2}:
 1  2  3
 4  5  6
julia> first(foo)
1

julia> first([-1:-2:-10])
-1

julia> first(1:2:0)         # empty range
1

In the Julia programming language, the function first(coll) is used to retrieve the first element of an iterable collection. If the collection is empty, it returns the start point of a Range.

Get the first element of an array:
```
julia> arr = [1, 2, 3, 4];
julia> first(arr)
1
```
This example returns the first element of the array arr.
Retrieve the first element of a tuple:
```
julia> tpl = (10, 20, 30);
julia> first(tpl)
10
```
It returns the first element of the tuple tpl.
Access the first element of a range:
```
julia> rng = 1:5;
julia> first(rng)
1
```
This example retrieves the start point of the range rng.
Handling an empty collection:
```
julia> empty_arr = Int[];
julia> first(empty_arr)
ERROR: ArgumentError: empty collection
```
When the collection is empty, an ArgumentError is raised. It's important to handle such cases appropriately.

Common mistake example:

julia> str = "Hello";
julia> first(str)
'H'

In this example, the first function returns the first character of the string str as a character literal, not as a string. If you want the first character as a string, you can use first(string(str)) instead.

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Examples

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