The `java.lang.NumberFormatException` is an exception that occurs when the Java runtime environment tries to convert a string into a number, but the string does not represent a valid number. In your case, the error message "for input string: "6"" might seem confusing at first since "6" should be a valid integer. However, there's likely more to the story. The full string causing the problem isn't shown in your message, but it's possible that there are non-digit characters involved. For instance, if the actual input string were `"6abc"`, this would throw a `NumberFormatException` because "abc" cannot be parsed as part of a number. Another possibility could be regional formatting differences, where a comma or other non-standard character is used as a decimal separator instead of a dot, which would also lead to this exception for Integer parsing. To handle this issue: 1. If you're trying to parse an integer and expect no decimal or other non-digit characters, use `Integer.parseInt()` or `Integer.valueOf()`, and ensure the entire string consists only of digits (and possibly a minus sign for negative numbers). ```java try { int value = Integer.parseInt("6"); } catch (NumberFormatException e) { System.out.println("Invalid integer format"); } ``` 2. If you're parsing a decimal number (float or double), use `Double.parseDouble()` or `Float.parseFloat()` and ensure the string follows the correct format for decimal numbers in your locale. ```java try { double value = Double.parseDouble("6.0"); } catch (NumberFormatException e) { System.out.println("Invalid number format"); } ``` 3. If the input may contain non-numeric characters that need to be ignored or handled, you can preprocess the string before parsing. 4. Always wrap the parsing operation in a try-catch block to handle the exception gracefully. [2024-01-17 23:12:08 | AI写代码神器 | 381点数解答]