An array that is not one-dimensional can be flattened in Ruby using the **`flatten` method**. It recursively flattens the array and returns a new array that is one-dimensional.


#    
## Syntax
```ruby
array.flatten
```
## Parameters
This method takes no parameters.

## Return value
A new array is returned that is one-dimensional.

## Code example
In the example below, we will create some dimensional arrays and flatten them to a one-dimensional array using the `flatten` method.



# create arrays
arr1 = [1, 2, [3, 4]]
arr2 = [[1, 2, 3,], [4, 5, 6]]
arr3 = ["a","b",["a", "b", ["a", "b"]]]

# flatten the arrays
a = arr1.flatten
b = arr2.flatten
c = arr3.flatten

# print out returned values
puts "#{a}"
puts "#{b}"
puts "#{c}"

How to flatten multi-dimensional arrays into one in Ruby

Syntax

Parameters

Return value

Code example