flutter - Dart 中字符串的默认值是多少？

Question

String 的默认值是多少？在 Dart 。

它必须是 '' 或 null .

String myString;
print(myString);
print(myString=='');
print(myString==null);

这将返回什么？

Answer 1

根据官方文档:

Uninitialized variables have an initial value of null.Even variables with numeric types are initially null because numbers—like everything else in Dart—are objects.

String lineCount;
assert(lineCount == null);

您可以查看此链接 https://dart.dev/guides/language/language-tour#default-value