Determine a value is INTEGER

[Pete]

Yeah, these things can be real pains...

Code: (Select All)

Do

    Input "Input a number: "; value!

    If InStr(Str$(value!), ".") = 0 Or InStr(Str$(value!), ".") And Val(Mid$(Str$(value!), InStr(Str$(value!), ".") + 1)) = 0 Then Print "The number is an integer." Else Print "The number is not an integer."

Loop

Looks like it would work, right? Wrong.

10.01 - is not an integer. Okay...
10.001- is not an integer. Okay... 
10.0001 - is not an integer. Okay... 
10.00001 - is not an integer. Okay... 
10.000001 - is an integer. OOPS!!!!!!!!

Taking it to the limits reveals the floating point problems we get in base2 math.

Edit: For fun, it does work if we make it a sting in the first place...

Code: (Select All)

Do

    Input "Input a number: "; a$

    If InStr(a$, ".") = 0 Or InStr(a$, ".") And Val(Mid$(a$, InStr(a$, ".") + 1)) = 0 Then Print "The number is an integer." Else Print "The number is not an integer."

Loop

Pete