相关疑难解决方法(0)

package arraypkg;

import java.util.Arrays;

public class Main
{
    private static void foo(Object o[])
    {
        System.out.printf("%s", Arrays.toString(o));
    }

    public static void main(String[] args)
    {
       Object []o=new Object[]{1,2,3,4,5};
       foo(o);                     //Passing an array of objects to the foo() method.

       foo(new Object[]{6,7,8,9}); //This is valid as obvious.

       Object[] o1 = {1, 2};      //This is also fine.
       foo(o1);

       foo({1,2});               //This looks something similar to the preceding one. This is however wrong and doesn't compile - not a statement.
    }
}

在前面的代码片段中,除最后一个之外的所有表达式都被编译并运行正常.虽然最后一个看起来类似于其立即语句的语句,但编译器发出编译时错误 - 非法启动表达式 - 而不是语句.为什么？