结合泛型使用，不然就只能写成for(Object o : T)。

缺点是没有下标，如下面代码

public class ForeachTest {    public static void main(String[] args) {        String[] s = {"kobe" , "tracy" , "tim" , "shark"};                StringBuffer sb = new StringBuffer();                for (int i =0 ; i < s.length ; i++){            if (i == s.length-1){                sb.append(s[i]);            }else {                sb.append(s[i]);                sb.append(",");            }        }        System.out.println(sb);    }}

kobe,tracy,tim,shark

如果用foreach来做

public class ForeachTest {    public static void main(String[] args) {        String[] s = {"kobe" , "tracy" , "tim" , "shark"};                StringBuffer sb = new StringBuffer();                    for (String str : s){            sb.append(str);            sb.append(","); //kobe,tracy,tim,shark, 多了一个逗号        }        //所以去截掉一部分        System.out.println(sb.substring(0 , sb.length()-1)); //kobe,tracy,tim,shark    }}