（28）运算符优先级
最后更新于：2022-04-01 10:58:23
## Java编程那些事儿28—运算符优先级
郑州游戏学院 陈跃峰
出自：[http://blog.csdn.net/mailbomb](http://blog.csdn.net/mailbomb)
**4.7 运算符优先级**
在实际的开发中，可能在一个运算式中出现多个运算符，那么计算时，就按照优先级级别的高低进行计算，级别高的运算符先运算，级别低的运算符后计算，具体运算符的优先级见下表：
运算符优先级表
<table style="BORDER-RIGHT: medium none; BORDER-TOP: medium none; MARGIN-LEFT: 69.2pt; BORDER-LEFT: medium none; BORDER-BOTTOM: medium none; BORDER-COLLAPSE: collapse" border="1" cellspacing="0" cellpadding="0"><tbody><tr><td style="padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; padding-top: 0cm; border: black 1pt solid;" width="57" valign="top"><div>优先级</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: black 1pt solid; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>运算符</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: black 1pt solid; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>结合性</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>1</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>() [] .</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>从左到右</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>2</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>! +(正) -(负) ~ ++ --</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>从右向左</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>3</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>* / %</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>从左向右</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>4</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>+(加) -(减)</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>从左向右</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>5</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div><< >> >>></div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>从左向右</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>6</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>< <= > >= instanceof</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>从左向右</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>7</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>==<span> !=</span></div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>从左向右</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>8</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>&(按位与)</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>从左向右</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>9</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>^</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>从左向右</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>10</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>|</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>从左向右</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>11</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>&&</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>从左向右</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>12</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>||</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>从左向右</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>13</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>?:</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85" valign="top"><div>从右向左</div></td></tr><tr><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; padding-left: 5.4pt; width: 42.55pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="57" valign="top"><div>14</div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 169.8pt; padding-right: 5.4pt; border-top: medium none; border-right: windowtext 1pt solid; padding-top: 0cm;" width="226" valign="top"><div>= += -= *= /= %= &= |= ^= ~= <<= >>=<span> >>>=</span></div></td><td style="border-bottom: black 1pt solid; border-left: medium none; padding-bottom: 0cm; padding-left: 5.4pt; width: 64.05pt; padding-right: 5.4pt; border-top: medium none; border-right: black 1pt solid; padding-top: 0cm;" width="85"><div>从右向左</div></td></tr></tbody></table>
说明：
1、 该表中优先级按照从高到低的顺序书写，也就是优先级为1的优先级最高，优先级14的优先级最低。
2、 结合性是指运算符结合的顺序，通常都是从左到右。从右向左的运算符最典型的就是负号，例如3+-4，则意义为3加-4，符号首先和运算符右侧的内容结合。
3、 instanceof作用是判断对象是否为某个类或接口类型，后续有详细介绍。
4、 注意区分正负号和加减号，以及按位与和逻辑与的区别
其实在实际的开发中，不需要去记忆运算符的优先级别，也不要刻意的使用运算符的优先级别，对于不清楚优先级的地方使用小括号去进行替代，示例代码：
~~~
int m = 12;
int n = m << 1 + 2;
int n = m << (1 + 2); //这样更直观
~~~
这样书写代码，更方便编写代码，也便于代码的阅读和维护。