hashset java

HashSet类的clear()方法 (HashSet Class clear() method)

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

  clear()方法在java.util包中可用。

• clear() method is used to clear all of the element exists from this HashSet.

  clear()方法用于清除此HashSet中存在的所有元素。

• clear() 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.

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

• clear() method does not throw an exception at the time of clearing elements.

  clear()方法在清除元素时不会引发异常。

Syntax:

句法：

    public void clear();

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 void, it returns nothing.

该方法的返回类型为void ，不返回任何内容。

Example:

例：

// Java program to demonstrate the example 
// of void clear() method of HashSet 
import java.util.*;
public class ClearOfHashSet {
public static void main(String[] args) {
// Instantiates a HashSet object
HashSet < String > hs = new HashSet < String > ();
// By using add() method is to add
// the given object of this HashSet 
hs.add("C");
hs.add("C++");
hs.add("JAVA");
hs.add("PHP");
hs.add("SFDC");
// Display HashSet
System.out.println("HashSet: " + hs);
// By using clear() method is to
// remove all of the elements exists
// in this HashSet
hs.clear();
//Display Modified HashSet
System.out.println("hs.clear(): " + hs);
}
}

Output

输出量

HashSet: [JAVA, C++, C, SFDC, PHP]
hs.clear(): []

翻译自: https://www.includehelp.com/java/hashset-clear-method-with-example.aspx

hashset java