Java HashSet contains（）方法与示例

admin管理员组

文章数量:1794759

Java HashSet contains（）方法与示例

HashSet类contains()方法 (HashSet Class contains() method)

• contains() method is available in Java.util package.

  contains()方法在java.util包中可用。

• contains() method is used to check the existence of the given object (ob) in this HashSet.

  contains()方法用于检查此HashSet中给定对象(ob)的存在。

• contains() 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.

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

• contains() method does not throw an exception at the time of testing the existence of the given object.

  在测试给定对象的存在时， contains()方法不会引发异常。

Syntax:

句法：

public boolean contains (Object ob);

Parameter(s):

参数：

• Object ob – represents the object whose existence is to be checked.

  对象ob –表示要检查其存在的对象。

Return value:

返回值：

The return type of the method is boolean, it returns true when the given object exists otherwise it returns false.

方法的返回类型为boolean ，当给定对象存在时返回true，否则返回false。

Example:

例：

// Java program to demonstrate the example // of boolean contains (Object ob) method of HashSet import java.util.*; public class ContainsOfHashSet { 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 contains() method is to // check whether the given object exists // or not exists in this HashSet boolean status = hs.contains("JAVA"); // Display Status System.out.println("hs.contains(JAVA): " + status); } }

Output

输出量

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

翻译自: www.includehelp/java/hashset-contains-method-with-example.aspx

本文标签： 示例方法javaHashSet