import java.util.Arrays; import java.util.List; public class Main { public static void main(String[] args) { List<String> listSymbol = Arrays.asList("doge-usdt", "btc-usdt", "ltc-usdt", "doge-btc", "doge-eth", "eth-usdt", "bnb-usdt"); System.out.println(listSymbol); } } 我要for循环list中元素怎么写

你可以使用 for-each 循环来遍历 List 中的元素。以下是在你的代码中添加 for 循环的示例：

import java.util.Arrays;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        List<String> listSymbol = Arrays.asList("doge-usdt", "btc-usdt", "ltc-usdt", "doge-btc", "doge-eth", "eth-usdt", "bnb-usdt");
        
        for (String symbol : listSymbol) {
            System.out.println(symbol);
        }
    }
}

在上述示例中，我们使用 for-each 循环迭代遍历了 List 中的元素。对于每个循环迭代，将当前元素赋值给变量 `symbol`，然后将其打印出来。

当你运行这段代码时，它会输出以下内容：

doge-usdt
btc-usdt
ltc-usdt
doge-btc
doge-eth
eth-usdt
bnb-usdt

这表明成功地使用 for 循环遍历了 List 中的所有元素，并将它们逐个打印出来。

相关问题

import java.io.*; import java.util.Arrays; import java.util.Scanner; public class FileTest { public static void main(String[] args) throws IOException { // 接收给定的一行字符串 Scanner scanner = new Scanner(System.in); String line = scanner.nextLine();

// 创建文件对象，并检查文件是否存在 File file = new File(line); if (!file.exists()) { System.out.println("文件不存在！"); return; } // 读取文件内容 BufferedReader reader = new BufferedReader(new FileReader(file)); String content = ""; String temp; while ((temp = reader.readLine()) != null) { content += temp + "\n"; } // 关闭文件读取器 reader.close(); // 输出文件内容 System.out.println("文件内容：\n" + content); } }

这段代码是一个读取文件并输出文件内容的Java程序。首先，通过Scanner接收用户输入的文件路径，然后判断文件是否存在。如果文件不存在，则输出提示信息并结束程序。如果文件存在，则创建文件读取器并读取文件内容，将读取到的内容存储在一个字符串变量中。最后，关闭文件读取器并输出文件内容。

声明一个 Student 类，属性包括姓名、学号、总成绩；生成 10 个 Student 类对象,并放在一个一维数组中,编写方法按总成绩进行排序,将排序后的对象 分别保持在Vector 、ArrayList、 HashTable类型的对象中,并遍历显示其中 元素的信息。 程序设计参考框架如下： import java,util.Vector; import java.util.ArrayList; import java.util.Hashtable; import java.util.Enumeration; import java.util.Iterator; public class Ex71 { public static void main (String[] args){

public class Student implements Comparable<Student>{
private String name;
private int id;
private int totalScore;

public Student(String name, int id, int totalScore){
this.name = name;
this.id = id;
this.totalScore = totalScore;
}

public String getName(){
return name;
}

public int getId(){
return id;
}

public int getTotalScore(){
return totalScore;
}

public void setName(String name){
this.name = name;
}

public void setId(int id){
this.id = id;
}

public void setTotalScore(int totalScore){
this.totalScore = totalScore;
}

public int compareTo(Student s){
return this.totalScore - s.totalScore;
}
}

import java.util.Vector;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.Enumeration;
import java.util.Iterator;

public class Ex71 {
public static void main (String[] args){
Student[] students = new Student[10];
students[0] = new Student("Tom", 1001, 80);
students[1] = new Student("Jerry", 1002, 90);
students[2] = new Student("Alice", 1003, 85);
students[3] = new Student("Bob", 1004, 70);
students[4] = new Student("Peter", 1005, 95);
students[5] = new Student("Mary", 1006, 65);
students[6] = new Student("John", 1007, 75);
students[7] = new Student("Lucy", 1008, 88);
students[8] = new Student("David", 1009, 92);
students[9] = new Student("Lily", 1010, 78);

// sort by total score
Arrays.sort(students);

// put sorted objects into Vector
Vector<Student> vector = new Vector<Student>();
for(Student s : students){
vector.add(s);
}

// put sorted objects into ArrayList
ArrayList<Student> arrayList = new ArrayList<Student>();
for(Student s : students){
arrayList.add(s);
}

// put sorted objects into Hashtable
Hashtable<Integer, Student> hashtable = new Hashtable<Integer, Student>();
int i = 1;
for(Student s : students){
hashtable.put(i++, s);
}

// display elements in Vector
System.out.println("Elements in Vector:");
Enumeration<Student> enumeration = vector.elements();
while(enumeration.hasMoreElements()){
Student s = enumeration.nextElement();
System.out.println("Name: " + s.getName() + ", ID: " + s.getId() + ", Total Score: " + s.getTotalScore());
}

// display elements in ArrayList
System.out.println("Elements in ArrayList:");
Iterator<Student> iterator = arrayList.iterator();
while(iterator.hasNext()){
Student s = iterator.next();
System.out.println("Name: " + s.getName() + ", ID: " + s.getId() + ", Total Score: " + s.getTotalScore());
}

// display elements in Hashtable
System.out.println("Elements in Hashtable:");
Enumeration<Integer> keys = hashtable.keys();
while(keys.hasMoreElements()){
Integer key = keys.nextElement();
Student s = hashtable.get(key);
System.out.println("Name: " + s.getName() + ", ID: " + s.getId() + ", Total Score: " + s.getTotalScore());
}
}
}