TIL: Ruby Splat Operator Builds Arrays

You can use the splat operator to coerce values into arrays.

The *thing convention tries to wrap thing in an array intelligently. For example:

x = *'billy ruffian'
# x = ['billy ruffian']

If you splat a nil, you get a zero length array:

x = *nil
# x = []

If you splat an array, it's unchanged:

x = *[1,2,3]
# x = [1,2,3]

If you splat a hash, the hash is unpacked:

x = *{name: 'billy'}
# x = [[:name, 'billy]]

If you splat a subarray during array construction, it gets flattened automatically:

x = [*[1,2], *[3,4]]
# x = [1,2,3,4]