string to integer in smalltalk

Question

i want to convert the input value in "Prompter prompt: aStringPrompt" into a integer value, how can i do that?

Answer 1

Two steps: (a) validate the input, and (b) convert.

You could validate like so: myString isAllDigits.

Converting is trivial: '1' asInteger. In Squeak, at least, this returns the integer 1. 'g1' asInteger returns 1, as does 'g1' asInteger. g asInteger returns nil.

So in summary:

"Given some input string s containing a decimal representation of a number, either return s in integer form, or raise an exception."
s := self getUserInput.
(s isAllDigits) ifFalse: [ Exception signal: '"', s, '" is not a (decimal) number' ].

^ s asInteger.