#    
## Overview 
The **`combination()` method** in `Ruby` takes an integer `n` as a parameter and produces combinations of length `n` for the elements of an array.

## Syntax
```ruby
array.combination(n)
```
## Parameter
**`n`**: The length of the combination of elements.

## Return value
This method returns all combinations of length `n` over the elements of the array.





# create an array
arr1 = [1, 2, 3, 4, 5]
arr2 = ["a", "b", "c", "d"]

# combine elements of the arrays
a = arr1.combination(2).to_a 
b = arr2.combination(3).to_a

puts "#{a}"   # combination in 2
puts "#{b}"

## Explanation

- Lines 2 and 3: We create arrays with 5 and 4 elements, respectively. `arr1` has integer elements while `arr2` has strings.

- Line 6: We call `combination()` on `arr1` to get all combinations of length `2`.

- Line 7: We call `combination()` on `arr2` to get all combinations of length `3`.

The `combination()` method returns `enumerator`. To get the array from the enumerator, we call the `to_a` method in lines 6 and 7.


How to get a combination of elements of an array in Ruby

Use Ruby's combination(n) method to generate and return all combinations of n elements from an array.