Variable Length Argument List, Asterisk Operator The last parameter of a method may be preceded by an asterisk(*), which is sometimes called the ‘splat’ operator. This indicates that more parameters may be passed to the function. Those parameters are collected up and an array is created. The asterisk operator may also precede an Array argument … Read more
In our case, NoMethodErrors due to nil references are by far the most common errors we see in our production environments. The new Hash#dig allows you to omit nil checks when accessing nested elements. Since hashes are best used for when the structure of the data is unknown, or volatile, having official support for this … Read more
The fact that you get a tuple on the RHS has nothing to do with the splat. The splat just unpacks your map iterator. What you unpack it into is decided by the fact that you’ve used tuple syntax: *whatever, instead of list syntax: [*whatever] or set syntax: {*whatever} You could have gotten a list … Read more
The * is the splat operator. It expands an Array into a list of arguments, in this case a list of arguments to the Hash.[] method. (To be more precise, it expands any object that responds to to_ary/to_a, or to_a in Ruby 1.9.) To illustrate, the following two statements are equal: method arg1, arg2, arg3 … Read more
Ruby 2.0 introduced keyword arguments, and ** acts like *, but for keyword arguments. It returns a Hash with key / value pairs. For this code: def foo(a, *b, **c) [a, b, c] end Here’s a demo: > foo 10 => [10, [], {}] > foo 10, 20, 30 => [10, [20, 30], {}] > … Read more
In Ruby and Perl 6 this has been called “splat”, and I think most people from those communities will figure out what you mean if you call it that. The Python tutorial uses the phrase “unpacking argument lists”, which is long and descriptive. It is also referred to as iterable unpacking, or in the case … Read more