I have this Python code:

# some_dic is a dictionary
value = some_dic.get(var_name, None)

How can I do the same in Crystal?

CodePudding user response：

The map type called dictionary in Python is called Hash in Crystal.

Values with an explicit fallback value can be retrieved using the Hash#fetch method:

numbers = {"Alice" => "0123", "Bob" => "0124"}
puts numbers.fetch("Charlie", "0000")

So in your case

value = some_dic.fetch(var_name, nil)

If your default value should be nil then there's the handy Hash#[]? method:

puts numbers["Charlie"]?

Read more about hashes in the language introduction: https://crystal-lang.org/reference/1.3/syntax_and_semantics/literals/hash.html