copy onwriterarraylist 在 Java 中包含()方法
原文:https://www . geeksforgeeks . org/copy onwriterarraylist-contains-method-in-Java/
包含 的(E e) 方法检查列表中是否存在给定的元素。如果元素至少出现一次，则函数返回 true，否则返回 false。
语法:
public boolean contains(Object o)
参数:该函数接受单个强制参数 o ，该参数指定要在列表中检查其外观的元素。
返回值:如果元素在列表中至少出现一次，函数返回真，否则返回假。
以下程序说明了上述功能:
程序 1:
// Java Program to illustrate the CopyOnWriteArrayList
// contains() method in Java
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// create object of CopyOnWriteArrayList
CopyOnWriteArrayList<Integer> ArrLis
= new CopyOnWriteArrayList<Integer>();
// Add elements
ArrLis.add(32);
ArrLis.add(67);
ArrLis.add(98);
ArrLis.add(100);
// print CopyOnWriteArrayList
System.out.println("CopyOnWriteArrayList: " + ArrLis);
// check using function
if (ArrLis.contains(100))
System.out.println("100 is present in the list");
else
System.out.println("100 is not present in the list");
// check using function
if (ArrLis.contains(20))
System.out.println("20 is present in the list");
else
System.out.println("20 is not present in the list");
}
}
输出:
CopyOnWriteArrayList: [32, 67, 98, 100]
100 is present in the list
20 is not present in the list
程序二:
// Java Program to illustrate the CopyOnWriteArrayList
// contains() method in Java
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// create object of CopyOnWriteArrayList
CopyOnWriteArrayList<String> ArrLis
= new CopyOnWriteArrayList<String>();
// Add elements
ArrLis.add("gopal");
ArrLis.add("gfg");
ArrLis.add("jgec");
ArrLis.add("sudo");
// print CopyOnWriteArrayList
System.out.println("CopyOnWriteArrayList: " + ArrLis);
// check using function
if (ArrLis.contains("gfg"))
System.out.println("'gfg' is present in the list");
else
System.out.println("'gfg' is not present in the list");
// check using function
if (ArrLis.contains("best"))
System.out.println("'best' is present in the list");
else
System.out.println("'best' is not present in the list");
}
}
输出:
CopyOnWriteArrayList: [gopal, gfg, jgec, sudo]
'gfg' is present in the list
'best' is not present in the list
版权属于：月萌API www.moonapi.com，转载请注明出处
