JAVA “：”无法遍历数组的所有元素问题

package helloWorld;import java.util.Arrays;public class ArrayCopy {public static void main(String[] args) {// TODO Auto-generated method stubint[] a = {8,5,7,4,6,3,1} ;Arrays.sort(a);for(int i:a)System.out.printf("%2d ",a[i]);//System.out.printf("%4d",b[i]);}}

出现错误的源代码

运行---------显示错误和部分结果

 3  5  6  7  8 Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 7at helloWorld.ArrayCopy.main(ArrayCopy.java:12)

经过更改代码

package helloWorld;import java.util.Arrays;public class ArrayCopy {public static void main(String[] args) {// TODO Auto-generated method stubint[] a = {8,5,7,4,6,3,1} ;Arrays.sort(a);for(int i=0; i < a.length; i ++)System.out.printf("%2d ",a[i]);//System.out.printf("%4d",b[i]);}}

运行：

 1  3  4  5  6  7  8