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Where does this error come from when converting from string to int in C #?

Closed due to the fact that off-topic participants Grundy , αλεχολυτ , PashaPash ♦ 24 Nov '16 at 16:50 .

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  • “Questions asking for help with debugging (“ why does this code not work? ”) Should include the desired behavior, a specific problem or error, and a minimum code for playing it right in the question . Questions without an explicit description of the problem are useless for other visitors. See How to create minimal, self-sufficient and reproducible example . " - Grundy, αλεχολυτ, PashaPash
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  • 3
    Show the conversion code. And look at the data in the debugger - Zufir
  • one
    What exactly is not clear in the line: The input line had the wrong format ? - Grundy
  • If you are given an exhaustive answer, mark it as correct (tick the selected answer). - andreycha

2 answers 2

This error occurs if the string does not contain a number. To softly convert a string to a number, use the TryParse() method:

 int number; bool result = int.TryParse("42", out number); // true int number2; bool result2 = int.TryParse("ololo42", out number2); // false
  • most likely there . instead of , or vice versa in the number. - Grundy
  • @Grundy in int'e no separator) - Trymount
  • @Trymount, another reason for the error :) - Grundy

The input string had the wrong format - it means that you are trying to convert a character string to an integer, while in the original character string not all characters are numbers. In order to figure out what went wrong - just look at what you pass to the conversion method. For example:

 string inputStr = "123a56"; int number; bool isNumeric = int.TryParse(inputStr, out number); if(isNumeric) { Console.WriteLine("Строка успешно преобразована в число"); } else { Console.WriteLine("Ошибка преобразования. Вы уверены, что '" + inputStr + "' число?"); }

The error associated with the DateTime may be falling because the input string is a composite format. This composite format is built incorrectly and looks like a date. And you were rightly told to use the Int32.TryParse Method .

Useful links for familiarization:

  1. FormatException
  2. Composite Formatting
  3. Method you use Int32.Parse Method (most likely)

If you want to use Int32.Parse , then the problem can be solved like this:

 string inputStr = "123a56"; try { int number = Int32.Parse(inputStr); Console.WriteLine("Строка успешно преобразована в число"); } catch(Exception ex) { Console.WriteLine("Ошибка преобразования. Вы уверены, что '" + inputStr + "' число?"); }

You can read about try-catch here:

  1. try-catch
  2. try-catch-finally