How to make sure a number is float in Erlang?

Question

io:format throws a badarg exception if the format is ~f but the argument is integer:

io:format("~f", [2]).

Adding 0.0 solves the problem bus there an elegant way?

io:format("~f", [2+0.0]).

Answer 1

• float(Number) convert Number to float
• list_to_float(String) convert String to float
• is_float(Term) returns true if Term is a float

Answer 2

If you don't care about the exact output, you can use:

io:format("~p", [Term]).

This will work with any term, but doesn't give you the same kind of formatting options as ~f would.

Answer 3

Either

io:format("~f", [2.0]).

or

io:format("~f", [float(2)]).

works.