一个可变的变量用关键字var来声明。

A mutable variable is declared with the keyword var.

youdao

如果你希望有可变的字段，那么使用var关键字。

If you want mutable fields, then use the keyword var.

youdao

如果元组中只包含字符串和数字，它可以做为关键字，如果它直接或间接的包含了可变对象，就不能当做关键字。

Tuples can be used as keys if they contain only strings, numbers, or tuples; if a tuple contains any mutable object either directly or indirectly, it cannot be used as a key.

youdao

如果元组中只包含字符串和数字，它可以做为关键字，如果它直接或间接的包含了可变对象，就不能当做关键字。

Tuples can be used as keys if they contain only strings, numbers, or tuples; if a tuple contains any mutable object either directly or indirectly, it cannot be used as a key.

youdao