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How can i test if a given string contains a valid number

Question: How can I test if a given string contains a valid number? Answer: Use one of the string to number function inside a try except block, and test for an exception. Example: function IsStrANumber(NumStr : string) : bool; begin result := true; try StrToInt(NumStr); except result := false; end; end; procedure TForm1.Button1Click(Sender: TObject); begin if IsStrANumber(Edit1.Text) then ShowMessage(Edit1.Text) else ShowMessage('Not a Number'); end;