集合的迭代操作:
把集合的元素一个一个的遍历取出来
package com.iterator;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
//集合元素的迭代和遍历操作
public class IteratorDemo {
public static void main(String[] args) {
List list = new ArrayList();
list.add("A");
list.add("B");
list.add("C");
list.add("D");
//方式1:for循环
for (int index = 0; index < list.size(); index++) {
System.out.println(list.get(index));
}
System.out.println("------------------------");
//方式2:for-each
for (Object ele : list) {
System.out.println(ele);
}
System.out.println("------------------------");
//方式3:使用迭代器Iterator()
Iterator it = list.iterator();
while(it.hasNext()){
System.out.println(it.next());
}
System.out.println("------------------------");
//方式4:使用for循环操作Iterator
for(Iterator it2 = list.iterator();it2.hasNext();){
System.out.println(it2.next());
}
}
}
A
B
C
D
------------------------
A
B
C
D
------------------------
A
B
C
D
------------------------
A
B
C
D