Java编译器为什么会给出“错误：找不到符号”？以下代码中的LinkedList降序Iterator？ [英] Why does Java compiler give "error: cannot find symbol" for LinkedList descendingIterator in the following code?

问题描述

为什么要这段代码：

import java.util.*;
class Playground {
    public static void main(String[ ] args) {
        List<Integer> l = new LinkedList<>();
        Iterator<Integer> i = l.descendingIterator();
    }
}

生成此编译器错误

./Playground/Playground.java:5: error: cannot find symbol
        Iterator<Integer> i = l.descendingIterator();
                               ^
  symbol:   method descendingIterator()
  location: variable l of type List<Integer>
1 error

• 以下是相关的 JavaDocs API


• 正在运行Java7。如果出现问题。以为它已经存在多年了。


• 这里是其他地方的罐头示例。


• 您可以从此处将代码复制/粘贴到此网站查看


• Here is the relevant JavaDocs API
• Running Java 7.. In case that is issue. Thought it had been around for donkeys years.
• Here is a canned example elsewhere.
• You could copy/paste code from here into this website to see,

推荐答案




List是接口，而LinkedList是List的实现

List is an interface and LinkedList is an implementation of List

您可以选择像

Iterator<Integer> i = ((LinkedList<Integer>)l).descendingIterator();

或将代码更改为以下内容：

or change your code to be the following:

import java.util.*;
class Playground {
    public static void main(String[ ] args) {
        LinkedList<Integer> l = new LinkedList<>();
        Iterator<Integer> i = l.descendingIterator();
    }
}

这篇关于Java编译器为什么会给出“错误：找不到符号”？以下代码中的LinkedList降序Iterator？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！