Tree_Set.first()

// Java code to illustrate first()
import java.util.*;
import java.util.TreeSet;
  
public class TreeSetDemo {
    public static void main(String args[])
    {
        // Creating an empty TreeSet
        TreeSet<Integer> tree = new TreeSet<Integer>();
  
        // Use add() method to add elements into the Set
        tree.add(14);
        tree.add(8);
        tree.add(200);
        tree.add(48);
        tree.add(7);
        tree.add(124);
  
        // Displaying the TreeSet
        System.out.println("TreeSet: " + tree);
  
        // Displaying the lowest element of the set
        System.out.println("The first element is: " + tree.first());
    }
}

TreeSet: [7, 8, 14, 48, 124, 200]
The first element is: 7

// Java code to illustrate first()
import java.util.*;
import java.util.TreeSet;
  
public class TreeSetDemo {
    public static void main(String args[])
    {
        // Creating an empty TreeSet
        TreeSet<String> tree = new TreeSet<String>();
  
        // Use add() method to add elements into the Set
        tree.add("Welcome");
        tree.add("To");
        tree.add("Geeks");
        tree.add("Ab");
        tree.add("TreeSet");
        tree.add("B");
  
        // Displaying the TreeSet
        System.out.println("TreeSet: " + tree);
  
        // Displaying the lowest element of the set
        System.out.println("The first element is: " + tree.first());
    }
}

TreeSet: [Ab, B, Geeks, To, TreeSet, Welcome]
The first element is: Ab

// Java代码演示first()
import java.util.*;
import java.util.TreeSet;
  
public class TreeSetDemo {
    public static void main(String[] args)
    {
        // 创建一个空的TreeSet
        TreeSet<String> tree = new TreeSet<String>();
  
        // 使用add()方法将元素添加到Set中
        tree.add("欢迎");
        tree.add("来到");
        tree.add("Geeks");
        tree.add("45");
        tree.add("100");
        tree.add("5");
  
        // 显示TreeSet
        System.out.println("TreeSet: " + tree);
  
        // 显示集合中最小的元素
        System.out.println("第一个元素是：" + tree.first());
    }
}

TreeSet：[100，45，5，Geeks，To，Welcome]
第一个元素是：100