Simple Mathematical Question 1

[Stretchwickster]

Hi,

I need to find the last digit of a 10-digit integer. I have tried to use Mod 10 but the number seems to be too large to use with the mod operator. Has anyone got any ideas?

 

[mikeEd]

How big is the number?

 

[Stretchwickster]

The number is, for example: 4294901765

 

[Stretchwickster]

Sorry, I forgot to mention it is a LongInt

 

[LucieLastic]

What about converting it to a string and taking the last digit that way?

NumString := inttoStr(num);
lastdigit := numString[length(numstring)];

lastDigitStr := strToInt(lastDigit);

There's probably a more elegant way of doing this...

lou

 

[Stretchwickster]

Thanks for the suggestion but the number is lost in the first IntToStr conversion and NumString ends up equalling: -65531 !!!

 

[LucieLastic]

Sorry, yes, doesn't work.

The number 4294901765 exceeds LongInt range. Int64 type may be required but I tried my suggestion and it doesn't work with that either.

lou

 

[LucieLastic]

hi

This worked for the few example numbers I tried :

procedure TForm1.Button1Click(Sender: TObject);
var num : int64;
s : string;
numb : integer;
begin
num := 4294901765;
numb := num mod 10;

s := inttostr(numb);

label1.Caption := s;
end;

...give a bit more testing...

lou

 

[Stretchwickster]

Let me try and explain in a better way than I have already!!

A function I use to get the Paradox version of a specified database table returns a LongInt variable called table_level containing the version number. However, the only way to view this number seems to be by using the following line:

showMessageFmt('%s is a Level %u table.', [table.TableName, table_level]);

Any other method of outputting gives a table_level value of -65531. So I guess by using %u, I am casting to an unsigned integer?? So i have tried assigning table_level to Cardinal, LongWord and other type of integers but to know avail. The original outputted number (4294901765) seems to disappear!

Can anyone help?!

 

[Stretchwickster]

Woohoo! I've solved it now. The only way to get at the number being outputted by the ShowMessageFmt box was to use the Format function and store the result in a string variable. I then used Lou's idea of grabbing the last character of the string before converting it back to a normal integer! Thanks for your help Lou - much appreciated

 

[colttaylor]

Wouldn't...

showMessageFmt('%s is a Level %u table.',
[table.TableName, (table_level mod 10)]);

...have done the same thing?