Flogging a dead horse - reading a number

[Remi Forax]

> From: "Kenneth Fogel" <kfogel at dawsoncollege.qc.ca>
> To: "amber-dev" <amber-dev at openjdk.org>
> Sent: Sunday, January 19, 2025 6:55:34 PM
> Subject: Flogging a dead horse - reading a number

> Hi,

Hello, 

> I have started a new course this past week, a first level Java course. Once we
> get past “Hello Moose” (in Canada we prefer this to Hello World) I present a
> simple program that calculates loan payments. Then I present an interactive
> version where I am forced to write:

> var loan = Double.parseDouble(readln("Loan: "));

> var interest = Double.parseDouble(readln("Interest: "));

> var term = Double.parseDouble(readln("Term: "));

> Its all going well until I must describe what Double.parseDouble is.

> I do not need a read for each numeric type. A read for doubles is all I think is
> necessary and then I could write:

> var loan = (readNum("Loan: ")); // loan is a double

> or if I need an integer:

> var numberOfCarrots = (int)readNum(“How many carrots do you need? “);

> Heck, if I were greedy, I’d ask that if you cast a readln this results in
> numeric input:

> var loan = (double) readln("Loan: ")); // Just like Python

Java is not a dynamically typed language, so no ! 
That's said, you are free to provide a library for your students. 

In my case, with my students, we first go from readln/println to IO.readln()/IO.println() and then we add Integer.parseInt() and Double.parseDouble(), 
so Double.parseDouble() is not alien at the time it is introduced. 

> But I’m not that greedy, today.

> Ken

regards, 
Rémi 
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