> 优先级高于 &

    if (2 & 2 > 1)
    {
        // something wrong?
        cout <<"I don't think this line could display..." <<endl ;            // 1)
    }//if

观察上述代码, 问: 语句 1) 能被执行么?

答案是: 不能执行. 

                       2 & 2 > 1        红色部分先判断, 因为 > 优先级高于 & .

  

    if ((2 & 2) > 1)              // (2 & 2)括号不能少
    {
        // something wrong?
        cout <<"I don't think this line could display..." <<endl ;            // 1)
    }//if

更多内容, 请参见:   http://www.cnblogs.com/walfud/articles/2050522.html