两种在swift中定义字符串变量的方法

我只是想知道这两种定义变量的形式是否彼此不同.或者应该在某些特殊情况下使用.

var string1: String  {
    return "ok"
}

var string2: String = "ok"

第一种方法叫做 computed property：

Classes, structures, and enumerations can define computed properties, which do not actually store a value. Instead, they provide a getter and an optional setter to retrieve and set other properties and values indirectly.

您使用的表单只为string1提供了一个getter,使其成为只读属性.

第二种方法通常是stored property：

A stored property is a constant or variable that is stored as part of an instance of a particular class or structure. Stored properties can be either variable stored properties (introduced by the var keyword) or constant stored properties (introduced by the let keyword).

在您的情况下,它是一个读写属性(使用var关键字声明).

根据具体情况应该使用哪个.但有时只能引入计算属性(例如,如果您提供扩展名).