What's the equivalent of C#'s int.TryParse() method in Ruby? [duplicate]

Question

Possible Duplicate:
Safe integer parsing in Ruby

int.Parse converts a string into an integer, but throws an exception if the string cannot be convert. int.TryParse doesn't throw an error when it can't convert the sting to an int, but rather returns 0 and a bool that says whether the string can be converted.

Is there something similar in Ruby?

Answer 1

There is no direct equivalent in Ruby. The two main options are:

1. Use Integer('42'). This is more like C#'s Int32.Parse, in that it will raise an Error.
2. Use String.to_i, ie: "42".to_i. This will return 0 if you pass in something which isn't at least partly convertible to an integer, but never cause an Error. (Provided you don't also provide an invalid base.) The integer portion of the string will be returned, or 0 if no integer exists within the string.

Answer 2

Integer(str) is probably the thing you need - Integer('123') will return 123 and Integer('123a') will throw exception.