Checks if a string is an anagram of another string (case-insensitive, ignores spaces, punctuation and special characters).

Use String.toLowerCase() and String.prototype.replaceAll() with an appropriate regular expression to remove unnecessary characters and convert the string to lowercase.
Use String.split(''), Iterable.sort(), in combination with the cascade operator (..) and Iterable.join('') to normalize both strings and check if their normalized forms are equal.

代码实现

bool isAnagram(String str1, String str2) {
  String normalize(String str) => (str
          .toLowerCase()
          .replaceAll(RegExp(r'[^a-z0-9]', caseSensitive: false), '')
          .split('')
            ..sort())
      .join('');
  return normalize(str1) == normalize(str2);
}

使用样例

isAnagram('iceman', 'cinema'); // true