treeset java

TreeSet类pollLast()方法 (TreeSet Class pollLast() method)

• pollLast() method is available in java.util package.

  pollLast()方法在java.util包中可用。

• pollLast() method is used to return the last highest element and then remove the element from this TreeSet.

  pollLast()方法用于返回最后一个最高元素，然后从此TreeSet中删除该元素。

• pollLast() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.

  pollLast()方法是一个非静态方法，只能通过类对象访问，如果尝试使用类名访问该方法，则会收到错误消息。

• pollLast() method does not throw an exception at the time of returning the highest element.

  返回最高元素时， pollLast()方法不会引发异常。

Syntax:

句法：

    public Element pollLast();

Parameter(s):

参数：

• It does not accept any parameter.

  它不接受任何参数。

Return value:

返回值：

The return type of the method is Element, it returns the last highest element from this TreeSet otherwise it returns null when no such element exists.

方法的返回类型为Element ，它返回此TreeSet中的最后一个最高元素，否则当不存在此类元素时返回null。

Example:

例：

// Java program to demonstrate the example 
// of Element pollLast() method of TreeSet 
import java.util.*;
public class PollLastOfTreeSet {
public static void main(String[] args) {
// Instantiates a TreeSet object
TreeSet < String > tree_set = new TreeSet < String > ();
// By using add() method is to add
//the given object of this TreeSet 
tree_set.add("C");
tree_set.add("C++");
tree_set.add("JAVA");
tree_set.add("PHP");
tree_set.add("SFDC");
// Display TreeSet
System.out.println("TreeSet: " + tree_set);
// By using pollLast() method is to return
// the last highest element and then remove
// the element exists from this TreeSet
Object last_highest = tree_set.pollLast();
// Display last_highest
System.out.println("tree_set.pollLast(): " + last_highest);
// Display Modified TreeSet
System.out.println("Modified TreeSet: " + tree_set);
}
}

Output

输出量

TreeSet: [C, C++, JAVA, PHP, SFDC]
tree_set.pollLast(): SFDC
Modified TreeSet: [C, C++, JAVA, PHP]

翻译自: https://www.includehelp.com/java/treeset-polllast-method-with-example.aspx

treeset java