科特林的Getters和Setters

Question

private val isEmpty: String
        get() = this.toString() //making this thing public rises an error: Getter visibility must be the same as property visibility.

Answer 1

getter和setter是在Kotlin中自动生成的。如果你写：

val isEmpty: Boolean

它等于以下Java代码：

private final Boolean isEmpty;

public Boolean isEmpty() {
    return isEmpty;
}

在您的例子中，private access修饰符是冗余的-isEmpty默认情况下是私有的，只能由getter访问。当您试图获取对象的isEmpty属性时，您将调用real中的get方法。为了更好地理解Kotlin中的getters/setters，下面的两个代码示例是相等的：

var someProperty: String = "defaultValue"

var someProperty: String = "defaultValue"
    get() = field
    set(value) { field = value }

val isEmpty: Boolean
  get() = field

var isEmpty: Boolean
    private set