flutter data_error ai_generated true

FormatException: Unexpected character (at character N) while parsing date string

ID: flutter/dart-format-exception

Also available as: JSON · Markdown · 中文
85%Fix Rate
82%Confidence
1Evidence
2023-11-05First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
Flutter 3.13.0 active — — —
Dart 3.1.0 active — — —
intl 0.18.1 active — — —

Root Cause

A date string parsed by intl or another package does not match the expected format pattern, often due to locale differences or malformed input.

generic

中文

由 intl 或其它包解析的日期字符串与预期的格式模式不匹配，通常是由于区域设置差异或输入格式错误。

Official Documentation

https://pub.dev/packages/intl

Workarounds

  1. 85% success Validate and sanitize the date string before parsing. Example: String cleaned = dateString.replaceAll(RegExp(r'[^0-9:/\- ]'), ''); DateTime parsed = DateFormat('yyyy-MM-dd HH:mm:ss').parse(cleaned); 
    Validate and sanitize the date string before parsing. Example: String cleaned = dateString.replaceAll(RegExp(r'[^0-9:/\- ]'), ''); DateTime parsed = DateFormat('yyyy-MM-dd HH:mm:ss').parse(cleaned);
  2. 90% success Use a flexible parser like DateTime.tryParse() or the intl package's DateFormat with multiple patterns. Example: DateTime? date = DateFormat('yyyy-MM-dd').tryParse(input) ?? DateFormat('MM/dd/yyyy').tryParse(input); 
    Use a flexible parser like DateTime.tryParse() or the intl package's DateFormat with multiple patterns. Example: DateTime? date = DateFormat('yyyy-MM-dd').tryParse(input) ?? DateFormat('MM/dd/yyyy').tryParse(input);
  3. 95% success Log the exact input string and expected format to debug the mismatch. Add a debug print: print('Parsing date: $input with format $pattern'); 
    Log the exact input string and expected format to debug the mismatch. Add a debug print: print('Parsing date: $input with format $pattern');

中文步骤

  1. Validate and sanitize the date string before parsing. Example: String cleaned = dateString.replaceAll(RegExp(r'[^0-9:/\- ]'), ''); DateTime parsed = DateFormat('yyyy-MM-dd HH:mm:ss').parse(cleaned);
  2. Use a flexible parser like DateTime.tryParse() or the intl package's DateFormat with multiple patterns. Example: DateTime? date = DateFormat('yyyy-MM-dd').tryParse(input) ?? DateFormat('MM/dd/yyyy').tryParse(input);
  3. Log the exact input string and expected format to debug the mismatch. Add a debug print: print('Parsing date: $input with format $pattern');

Dead Ends

Common approaches that don't work:

  1. Change the date format pattern randomly until it works 90% fail

    Without understanding the input format, random changes are unlikely to match the actual string.

  2. Use try-catch to swallow the exception 80% fail

    Silencing the error does not fix the underlying data issue and may lead to silent failures.