基于可变值的 Kotlin 和惯用的编写方式，'if not null, else......'

假设我们有以下代码:

class QuickExample {

    fun function(argument: SomeOtherClass) {
        if (argument.mutableProperty != null ) {
            doSomething(argument.mutableProperty)
        } else {
            doOtherThing()
        }
    }

    fun doSomething(argument: Object) {}

    fun doOtherThing() {}
}

class SomeOtherClass {
    var mutableProperty: Object? = null
}

与Java中不同的是，在Java中，您可能会在运行时担心空引用的取消，但这不会编译-这是非常正确的.当然，在‘if’中，一旦mutableProperty不再为NULL.

My question is what's the best way to handle this?

A few options are apparent. Without using any new Kotlin language features, the simplest way is obviously to copy the value to a method-scope one that won't subsequently change.

There's this:

fun function(argument: SomeOtherClass) {
    argument.mutableProperty?.let {
        doSomething(it)
        return
    }
    doOtherThing()
}

这有一个明显的缺点，即您需要提前返回或避免执行后续代码-在某些较小的上下文中可以，但有一些问题.

Then there's this possibility:

fun function(argument: SomeOtherClass) {
    argument.mutableProperty.let {
        when {
            it != null -> {
                doSomething(it)
            }
            else -> {
                doOtherThing()
            }
        }
    }
}

but whilst it has greater clarity of purpose, arguably it's more unwieldy and verbose than the Java-style way of dealing with this.

我遗漏了什么吗？有没有更好的习惯用法来实现这一点？