Question

What is the correct way to check if a value is a date/number in Delphi?

I know other languages have functions like isDate and isNaN, but what is the Delphi equivalent? at the minute I have this

function isNumeric(s1:string):boolean; begin       // will throw exception if its not a number   // there must be a better way to do this!!   try      StrTofloat(s1);        result :=  TRUE ;      except        result := FALSE;       end; end; 

But throwing exceptions cant be good, and it makes debugging hard as I keep seeing the exception dialogue every time the code is called.

Answer 1

For integers, you could use TryStrToInt to check and convert without throwing exceptions:

function TryStrToInt(const s: string; out i : integer): boolean; 

I’m not absolutely sure there is a full equivalent for floats, though, so you might need to use StrToFloat() and accept the possibility of a TFormatException.