Java中的 CopyOnWriteArrayList iterator() 方法

CopyOnWriteArrayList的iterator()方法以正确的顺序返回此列表中元素的迭代器。迭代器不支持 remove 方法。

句法：

public Iterator iterator()

参数：该函数不接受任何参数。

返回值：该函数返回列表中元素的迭代器。

下面的程序说明了上述函数：

方案一：

// Java Program to illustrate the CopyOnWriteArrayList
// iterator() 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 ArrLis
            = new CopyOnWriteArrayList();
  
        // Add elements
        ArrLis.add(32);
        ArrLis.add(67);
        ArrLis.add(67);
        ArrLis.add(100);
  
        // print CopyOnWriteArrayList
        System.out.println("CopyOnWriteArrayList: " + ArrLis);
  
        // Call iterator() method of
        Iterator iteratorVals = ArrLis.iterator();
  
        // Print elements of iterator
        // created from CopyOnWriteArrayList
        System.out.println("The iterator values"
                           + " of CopyOnWriteArrayList are:");
  
        // prints the elements using an iterator
        while (iteratorVals.hasNext()) {
            System.out.println(iteratorVals.next());
        }
    }
}

输出：

CopyOnWriteArrayList: [32, 67, 67, 100]
The iterator values of CopyOnWriteArrayList are:
32
67
67
100

方案二：

// Java Program to illustrate the CopyOnWriteArrayList
// iterator() 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 ArrLis
            = new CopyOnWriteArrayList();
  
        // Add elements
        ArrLis.add("gopal");
        ArrLis.add("gfg");
        ArrLis.add("jgec");
        ArrLis.add("sudo");
  
        // print CopyOnWriteArrayList
        System.out.println("CopyOnWriteArrayList: " + ArrLis);
  
        // Call iterator() method of
        Iterator iteratorVals = ArrLis.iterator();
  
        // Print elements of iterator
        // created from CopyOnWriteArrayList
        System.out.println("The iterator values"
                           + " of CopyOnWriteArrayList are:");
  
        // prints the elements using an iterator
        while (iteratorVals.hasNext()) {
            System.out.println(iteratorVals.next());
        }
    }
}

输出：

CopyOnWriteArrayList: [gopal, gfg, jgec, sudo]
The iterator values of CopyOnWriteArrayList are:
gopal
gfg
jgec
sudo

参考： https: Java/util/concurrent/CopyOnWriteArrayList.html#iterator–