check Input

[Nicholas Wilson via Digitalmars-d-learn]

On Monday, 17 April 2017 at 11:51:45 UTC, dennis wrote:
>
> Hi,
> try to build a little programm, but need to know
> how to check the input.
>
> For example:  input only numbers: 0 - 9 but 1.5 for example is 
> ok.
>
> thanks

I will point you to Ali's book (free), it goes through the basics 
of input and output.

http://ddili.org/ders/d.en/index.html

It is better for you to discover, however don't be afraid to ask 
if you get stuck.