containsall

向量类containsAll()方法 (Vector Class containsAll() method)

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

  containsAll()方法在java.util包中可用。

• containsAll() method is used to test the existence of all the elements of this Vector in the given Collection (co).

  containsAll()方法用于测试给定Collection(co)中此Vector的所有元素的存在。

• containsAll() 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.

  containsAll()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。

• containsAll() method may throw an exception at the time of checking the existence of the collection.

  在检查集合是否存在时， containsAll()方法可能会引发异常。

  NullPointerException: This exception may throw when the given parameter is null exists.

  NullPointerException ：当给定参数为null时，可能引发此异常。

Syntax:

句法：

    public boolean containsAll(Collection co);

Parameter(s):

参数：

• Collection co – represents the Collection object whose element will be checked for the existence in this Vector.

  Collection co –表示Collection对象，将检查其元素是否存在于此Vector中。

Return value:

返回值：

The return type of the method is boolean, it returns true when this Vector hold all of the given Collection elements otherwise it returns false.

方法的返回类型为boolean ，当此Vector包含所有给定的Collection元素时，它返回true ，否则返回false 。

Example:

例：

// Java program to demonstrate the example 
// of boolean containsAll(Collection co) method 
// of Vector 
import java.util.*;
public class ContainsAllOfVector {
public static void main(String[] args) {
// Instantiates a Vector object  with
// initial capacity of "10"
Vector < String > v = new Vector < String > (10);
ArrayList arr_l = new ArrayList();
// By using add() method is to add the
// elements in this v
v.add("C");
v.add("C++");
v.add("JAVA");
// By using add() method is to add the
// elements in this arr_l
arr_l.add("C");
arr_l.add("C++");
arr_l.add("SFDC");
// Display Vector and ArrayList
System.out.println("v: " + v);
System.out.println("arr_l: " + arr_l);
// By using containsAll(arr_l) method is to
// check whether this vector contains all of the
// elements in the given collection arr_l or not
boolean status = v.containsAll(arr_l);
// Display status
System.out.println("v.containsAll(arr_l): " + status);
}
}

Output

输出量

v: [C, C++, JAVA]
arr_l: [C, C++, SFDC]
v.containsAll(arr_l): false

翻译自: https://www.includehelp.com/java/vector-containsall-method-with-example.aspx

containsall