java for新循环_java新特性-新式for循环(For_Each)
package com.test.For_Each;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class ForTest
{
public static void main(String args[])
{
int arr[] = {1, 2, 3, 4, 5, 6, 7, 8};
/**
* 新式写法
*/
for (int a : arr)
System.out.println(a);
/**
* 旧式写法
*/
for (int i = 0; i < arr.length; i++)
System.out.println(arr[i]);
String arr2[] = {"好","流","哦","!!"};
for(String a2 : arr2)
System.out.println(a2);
int arr3[][] = { {1,2,3},{4,5,6,},{7,8,9}};
for(int a31[] : arr3)
{
for(int a32 : a31)
{
System.out.println(a32);
}
System.out.println();
}
List list = new ArrayList();
list.add("好");
list.add("流");
list.add("哦");
list.add("!!");
/**
* 根据集合类长度遍历
*/
for(int i=0;i
{
System.out.println(list.get(i));
}
/**
* 根据迭代器遍历
*/
for(Iterator i = list.iterator();i.hasNext();)
{
System.out.println(i.next());
}
/**
* 根据新式for-each遍历
*/
for(String element : list)
System.out.println(element);
}
}
package com.test.For_Each; import java.util.ArrayList; import java.util.Iterator; import java.util.List; public class ForTest { public static void main(String args[]) { int arr[] = {1, 2, 3, 4, 5, 6, 7, 8}; /** * 新式写法 */ for (int a : arr) System.out.println(a); /** * 旧式写法 */ for (int i = 0; i < arr.length; i++) System.out.println(arr[i]); String arr2[] = {"好","流","哦","!!"}; for(String a2 : arr2) System.out.println(a2); int arr3[][] = { {1,2,3},{4,5,6,},{7,8,9}}; for(int a31[] : arr3) { for(int a32 : a31) { System.out.println(a32); } System.out.println(); } List list = new ArrayList(); list.add("好"); list.add("流"); list.add("哦"); list.add("!!"); /** * 根据集合类长度遍历 */ for(int i=0;i { System.out.println(list.get(i)); } /** * 根据迭代器遍历 */ for(Iterator i = list.iterator();i.hasNext();) { System.out.println(i.next()); } /** * 根据新式for-each遍历 */ for(String element : list) System.out.println(element); } }