Java 基础之java运算符 ╰+哭是因爲堅強的太久メ 2022-10-09 12:26 125阅读 0赞 运算符 ,顾名思义就是用于计算的 符号。 按 功能分为:赋值运算符、算术运算符、关系 运算符和 逻辑运算 符 按操作数的个数 分类:单 目 运算符、双目运算符、三 目运算符 运算符 的 目: 运算符能连接操作数的个数称为运算符的目 运算符 的优先级:优先级是指在一个表达式中出现多个不同运算符,在进行计算时运算符执行的先后 次序。 运算符的结合 方向:结合方向又称为结合性,是指当一个操作数连接两个同一优先级的运算符时,按运算符的结合性所规定的结合 方向 处理。 **赋值运算符** “=”,是Java语言中最简单,也是最常用的运算符。 赋值运算用于将赋值运算符右侧表达式的结果赋予赋值运算符左侧的变量。 int english = 92; 赋值运算符具有自右向左的结合性 int a,b,c; //同时声明三个变量 a = b = c = 1; //自右向左赋值 **算术运算符** <table style="width:666px;"> <tbody> <tr> <td style="vertical-align:top;width:152pt;"> <p style="margin-left:0in;text-align:left;"><span style="color:#000000;"><strong>运算符</strong></span></p> </td> <td style="vertical-align:top;width:164pt;"> <p style="margin-left:0in;text-align:left;"><span style="color:#000000;"><strong>功能</strong></span></p> </td> <td style="vertical-align:top;width:257px;"> <p style="margin-left:0in;text-align:left;"><span style="color:#000000;"><strong>示例</strong></span></p> </td> </tr> <tr> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:152pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">+</span> </p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:164pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">加法运算</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:257px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">表达式</span><span style="color:#000000;">1+2</span><span style="color:#000000;">计算结果为</span><span style="color:#000000;">3</span></p> </td> </tr> <tr> <td style="text-align:justify;vertical-align:top;width:152pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">-</span> </p> </td> <td style="text-align:justify;vertical-align:top;width:164pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">减法运算</span></p> </td> <td style="text-align:justify;vertical-align:top;width:257px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">表达式</span><span style="color:#000000;">2-1</span><span style="color:#000000;">计算结果为</span><span style="color:#000000;">1</span></p> </td> </tr> <tr> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:152pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">*</span> </p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:164pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">乘法运算</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:257px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">表达式</span><span style="color:#000000;">2*2</span><span style="color:#000000;">计算结果为</span><span style="color:#000000;">4</span></p> </td> </tr> <tr> <td style="text-align:justify;vertical-align:top;width:152pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">/ </span></p> </td> <td style="text-align:justify;vertical-align:top;width:164pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">除法运算</span></p> </td> <td style="text-align:justify;vertical-align:top;width:257px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">表达式</span><span style="color:#000000;">4/2</span><span style="color:#000000;">计算结果为</span><span style="color:#000000;">2</span></p> </td> </tr> <tr> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:152pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">%</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:164pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">模运算</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:257px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">表达式</span><span style="color:#000000;">5%2</span><span style="color:#000000;">计算结果为</span><span style="color:#000000;">1</span></p> </td> </tr> </tbody> </table> 在算术运算符中,还存在两个较为独特的单目运算符,分别是自增和自减 自增和自减运算符分别用于使变量值自增1或自减1。 ![20210624210603341.png][]![20210624210618390.png][]![20210624210631353.png][] 变量a、b 的值均为6 ![20210624210733511.png][] ![20210624210739654.png][]![20210624210747980.png][] 变量a 的值为6,变量b 的值为5 **复合赋值运算符** <table style="width:665px;"> <tbody> <tr> <td style="vertical-align:top;width:172pt;"> <p style="margin-left:0in;text-align:left;"><span style="color:#000000;"><strong>运算符</strong></span></p> </td> <td style="vertical-align:top;width:224pt;"> <p style="margin-left:0in;text-align:left;"><span style="color:#000000;"><strong>功能</strong></span></p> </td> <td style="vertical-align:top;width:225px;"> <p style="margin-left:0in;text-align:left;"><span style="color:#000000;"><strong>示例</strong></span></p> </td> </tr> <tr> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:172pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">+=</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:224pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">加法运算</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:225px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">int a=10; a+=2 </span><span style="color:#000000;">等效于</span><span style="color:#000000;">a=a+2; a=12</span></p> </td> </tr> <tr> <td style="text-align:justify;vertical-align:top;width:172pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">-</span><span style="color:#000000;">= </span></p> </td> <td style="text-align:justify;vertical-align:top;width:224pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">减法运算</span></p> </td> <td style="text-align:justify;vertical-align:top;width:225px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">int a=10; a-=2 </span><span style="color:#000000;">等效于</span><span style="color:#000000;">a=a-2; a=8</span></p> </td> </tr> <tr> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:172pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">*</span><span style="color:#000000;">=</span> </p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:224pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">乘法运算</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:225px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">int a=10; a*=2 </span><span style="color:#000000;">等效于</span><span style="color:#000000;">a=a*2; a=20</span></p> </td> </tr> <tr> <td style="text-align:justify;vertical-align:top;width:172pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">/= </span></p> </td> <td style="text-align:justify;vertical-align:top;width:224pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">除法运算</span></p> </td> <td style="text-align:justify;vertical-align:top;width:225px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">int a=10; a/=2 </span><span style="color:#000000;">等效于</span><span style="color:#000000;">a=a/2; a=5</span></p> </td> </tr> <tr> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:172pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">%=</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:224pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">模运算</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:225px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">int a=10; a%=2 </span><span style="color:#000000;">等效于</span><span style="color:#000000;">a=a%2; a=0</span></p> </td> </tr> </tbody> </table> **关系运算符** <table style="width:672px;"> <tbody> <tr> <td style="vertical-align:top;width:209pt;"> <p style="margin-left:0in;text-align:left;"><span style="color:#000000;"><strong>运算符</strong></span></p> </td> <td style="vertical-align:top;width:261pt;"> <p style="margin-left:0in;text-align:left;"><span style="color:#000000;"><strong>功能</strong></span></p> </td> <td style="vertical-align:top;width:159px;"> <p style="margin-left:0in;text-align:left;"><span style="color:#000000;"><strong>示例</strong></span></p> </td> </tr> <tr> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:209pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">></span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:261pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">比较大于关系</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:159px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">表达式</span><span style="color:#000000;">2>1 </span><span style="color:#000000;">计算结果为“</span><span style="color:#000000;">True”</span></p> </td> </tr> <tr> <td style="text-align:justify;vertical-align:top;width:209pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">< </span></p> </td> <td style="text-align:justify;vertical-align:top;width:261pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">比较小于关系</span></p> </td> <td style="text-align:justify;vertical-align:top;width:159px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">表达式</span><span style="color:#000000;">2<1 </span><span style="color:#000000;">计算结果为“</span><span style="color:#000000;">False”</span></p> </td> </tr> <tr> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:209pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">>= </span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:261pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">比较大于等于关系</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:159px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">表达式</span><span style="color:#000000;">2>=1 </span><span style="color:#000000;">计算结果为“</span><span style="color:#000000;">True”</span></p> </td> </tr> <tr> <td style="text-align:justify;vertical-align:top;width:209pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;"><= </span></p> </td> <td style="text-align:justify;vertical-align:top;width:261pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">比较小于等于关系</span></p> </td> <td style="text-align:justify;vertical-align:top;width:159px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">表达式</span><span style="color:#000000;">2<=1 </span><span style="color:#000000;">计算结果为“</span><span style="color:#000000;">False”</span></p> </td> </tr> <tr> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:209pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">==</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:261pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">比较相等关系</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:159px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">表达式</span><span style="color:#000000;">2==1 </span><span style="color:#000000;">计算结果为“</span><span style="color:#000000;">False”</span></p> </td> </tr> <tr> <td style="background-color:#FFFFFF;text-align:justify;vertical-align:top;width:209pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">!=</span></p> </td> <td style="background-color:#FFFFFF;text-align:justify;vertical-align:top;width:261pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">比较不相等关系</span></p> </td> <td style="background-color:#FFFFFF;text-align:justify;vertical-align:top;width:159px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">表达式</span><span style="color:#000000;">2!=1 </span><span style="color:#000000;">计算结果为“</span><span style="color:#000000;">True”</span></p> </td> </tr> </tbody> </table> **逻辑运算符** <table style="width:676px;"> <tbody> <tr> <td style="vertical-align:top;width:120pt;"> <p style="margin-left:0in;text-align:left;"><span style="color:#000000;"><strong>运算符</strong></span></p> </td> <td style="vertical-align:top;width:312pt;"> <p style="margin-left:0in;text-align:left;"><span style="color:#000000;"><strong>功能</strong></span></p> </td> <td style="vertical-align:top;width:202px;"> <p style="margin-left:0in;text-align:left;"><span style="color:#000000;"><strong>示例</strong></span></p> </td> </tr> <tr> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:120pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">&&</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:312pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">与运算,即同时成立,缺一不可</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:202px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">a>b&&c>d</span><span style="color:#000000;">:只有左右两个表达式的值都为</span><span style="color:#000000;">true</span><span style="color:#000000;">, 整个结果才为</span><span style="color:#000000;">True</span><span style="color:#000000;">。只要有一个表达式为</span><span style="color:#000000;">false</span><span style="color:#000000;">,则整个表达式为</span><span style="color:#000000;">False</span></p> </td> </tr> <tr> <td style="text-align:justify;vertical-align:top;width:120pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">|| </span></p> </td> <td style="text-align:justify;vertical-align:top;width:312pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">或运算, 即两者中有一个成立即可</span></p> </td> <td style="text-align:justify;vertical-align:top;width:202px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">a>b||c>d</span><span style="color:#000000;">:左右两个表达式中只要有一个成立就为</span><span style="color:#000000;">true</span><span style="color:#000000;">,只有两个都为</span><span style="color:#000000;">false</span><span style="color:#000000;">才为</span><span style="color:#000000;">false</span></p> </td> </tr> <tr> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:120pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">! </span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:312pt;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">非运算,取反</span></p> </td> <td style="background-color:#f3ebef;text-align:justify;vertical-align:top;width:202px;"> <p style="margin-left:0in;text-align:justify;"><span style="color:#000000;">!(a>b)</span><span style="color:#000000;">:如果表达式</span><span style="color:#000000;">a>b </span><span style="color:#000000;">为</span><span style="color:#000000;">false</span><span style="color:#000000;">,则进行取反运算后为</span><span style="color:#000000;">true</span><span style="color:#000000;">;如果表达式</span><span style="color:#000000;">a>b</span><span style="color:#000000;">为</span><span style="color:#000000;">true</span><span style="color:#000000;">,则进行取反运算后为</span><span style="color:#000000;">false</span></p> </td> </tr> </tbody> </table> **三目运算符**可以快速的帮我们实现条件的判断,语法如下: 布尔表达式?表达式1:表达式2 条件表达式的结果由布尔表达式决定,如果布尔表达式的值为true,则返回表达1的值,否则返回表达式2的值。 [20210624210603341.png]: https://img-blog.csdnimg.cn/20210624210603341.png [20210624210618390.png]: https://img-blog.csdnimg.cn/20210624210618390.png [20210624210631353.png]: /images/20221005/194c1f5f0a8f4163bb5729ab52ee89d9.png [20210624210733511.png]: https://img-blog.csdnimg.cn/20210624210733511.png [20210624210739654.png]: https://img-blog.csdnimg.cn/20210624210739654.png [20210624210747980.png]: /images/20221005/a06e4d98253c4267b13eacf79264634f.png
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