Ruby Language Arrays Manipulating Array Elements
Example
Adding elements:
[1, 2, 3] << 4
# => [1, 2, 3, 4]
[1, 2, 3].push(4)
# => [1, 2, 3, 4]
[1, 2, 3].unshift(4)
# => [4, 1, 2, 3]
[1, 2, 3] << [4, 5]
# => [1, 2, 3, [4, 5]]
Removing elements:
array = [1, 2, 3, 4]
array.pop
# => 4
array
# => [1, 2, 3]
array = [1, 2, 3, 4]
array.shift
# => 1
array
# => [2, 3, 4]
array = [1, 2, 3, 4]
array.delete(1)
# => 1
array
# => [2, 3, 4]
array = [1,2,3,4,5,6]
array.delete_at(2) // delete from index 2
# => 3
array
# => [1,2,4,5,6]
array = [1, 2, 2, 2, 3]
array - [2]
# => [1, 3] # removed all the 2s
array - [2, 3, 4]
# => [1] # the 4 did nothing
Combining arrays:
[1, 2, 3] + [4, 5, 6]
# => [1, 2, 3, 4, 5, 6]
[1, 2, 3].concat([4, 5, 6])
# => [1, 2, 3, 4, 5, 6]
[1, 2, 3, 4, 5, 6] - [2, 3]
# => [1, 4, 5, 6]
[1, 2, 3] | [2, 3, 4]
# => [1, 2, 3, 4]
[1, 2, 3] & [3, 4]
# => [3]
You can also multiply arrays, e.g.
[1, 2, 3] * 2
# => [1, 2, 3, 1, 2, 3]
