正如我们在 swift 中定义的
常量与let
带有var的变量
如何在flutter中定义？
最佳答案
变量:
var number = 42;
常量:
If you never intend to change a variable, use final or const, either instead of var or in addition to a type. A final variable can be set only once; a const variable is a compile-time constant. (Const variables are implicitly final.) A final top-level or class variable is initialized the first time it’s used.
final name = 'Bob'; // Without a type annotation
final String nickname = 'Bobby';
Use const for variables that you want to be compile-time constants. If the const variable is at the class level, mark it static const. Where you declare the variable, set the value to a compile-time constant such as a number or string literal, a const variable, or the result of an arithmetic operation on constant numbers:
const bar = 1000000; // Unit of pressure (dynes/cm2)
const double atm = 1.01325 * bar; // Standard atmosphere
更多信息请参见:https://dart.dev/guides/language/language-tour#variables
关于android - flutter中如何定义变量和常量？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/57966620/