Ignoring a Value with _ (Underscore)
If we didn’t need to capture a value during the match, we could use the special variable _ (an underscore). This acts like a variable but immediately discards any value given to it—in a pattern match, it is like a wildcard saying, “I’ll accept any value here.” The following example matches any three-element list that has a 1 as its first element.
| | iex> [1, _, _] = [1, 2, 3] |
| | [1, 2, 3] |
| | iex> [1, _, _] = [1, "cat", "dog"] |
| | [1, "cat", "dog"] |
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