Question

此代码可能存在很多问题，无法在单个帖子中回答。我的主要问题是我试图通过列表理解来减少for循环的数量。

var drinksToday: MutableList<String> = mutableListOf()
lateinit var adapter: ArrayAdapter<String>

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    addButton.setOnClickListener {
        drinksToday.add(0, "250 ml")

        // Print to check addition to list
        println(drinksToday.toString())
        }

    if (savedInstanceState != null) {
        savedInstanceState.run {
            val list = getStringArray(EXTRA_LIST)
            if (list != null) {
                drinksToday = list.toMutableList<String>()
            }
        }
    }

    adapter = ArrayAdapter(this, android.R.layout.simple_list_item_1, drinksToday)
    drinksTodayList.adapter = adapter
}

override fun onSaveInstanceState(outState: Bundle?) {
    super.onSaveInstanceState(outState)

    outState?.run {
        putStringArray(EXTRA_LIST, drinksToday.toTypedArray())
    }
}

Answer 1

列表理解并不是唯一的改进。也可以通过直接在元素上进行迭代来摆脱for i in len(range(reqSoupElems))反图案：

time = [timeRegex.search(str(element)).group() for element in reqSoupElems]

使用.append进行列表理解

1 个答案: