Java 中的算术运算符

原文： https://javabeginnerstutorial.com/core-java-tutorial/java-arithmetic-operator/

在本节中，我们将学习算术，运算符，优先级和运算符关联。

运算符优先级

优先级决定在同一计算中存在多个运算符的情况下，首先求值哪个运算符。

运算符优先级表

运算符优先级（从高到低）
后缀expr++ expr—
一元++expr —expr +expr –expr ~ !
乘法 / %
加法+ –
移位<< >> >>>
关系< > <= >= instanceof
相等== !=
按位与&
按位异或^
按位或|
逻辑与&&
逻辑或||
三元?:
赋值= += -= = /= %= &= ^= |= <<= >>= >>>=

优先级示例

  1. /*
  2.  * Here we will see the effect of precedence in operators life
  3.  */
  4. class OperatorPrecedenceExample {
  6.     public static void main(String args[]) {
  7.         int i = 40;
  8.         int j = 80;
  9.         int k = 40;
  11.         int l = i + j / k;
  12.         /*
  13.          * In above calculation we are not using any bracket. So which operator
  14.          * will be evaluated first is decided by Precedence. As precedence of
  15.          * divison(/) is higher then plus(+) as per above table so divison will
  16.          * be evaluated first and then plus.
  17.          *
  18.          * So the output will be 42.
  19.          */
  21.         System.out.println("value of L :" + l);
  23.         int m = (i + j) / k;
  24.         /*
  25.          * In above calculation brackets are used so precedence will not come in
  26.          * picture and plus(+) will be evaluated first and then divison()/. So
  27.          * output will be 3
  28.          */
  30.         System.out.println("Value of M:" + m);
  31.     }
  32. }

运算符关联性

如果两个运算符在计算中具有相同的优先级，则将使用运算符的关联性来决定首先执行哪个运算符。

关联性示例

  1. package jbt.bean;
  3. /*
  4.  * Here we will see the effect of precedence in operators life
  5.  */
  6. public class OperatorAssociativityExample {
  8.     public static void main(String args[]) {
  9.         int i = 40;
  10.         int j = 80;
  11.         int k = 40;
  13.         int l = i / k * 2 + j;
  14.         /*
  15.          * In above calculation we are not using any bracket. And there are two
  16.          * operator of same precedence(divion and multiplication) so which
  17.          * operator(/ or *) will be evaluated first is decided by association.
  18.          * Associativity of * & / is left to right. So divison will be evaluated
  19.          * first then multiplication.
  20.          *
  21.          * So the output will be 82.
  22.          */
  24.         System.out.println("value of L :" + l);
  26.         int m = i / (k * 2) + j;
  27.         /*
  28.          * In above calculation brackets are used so associativity will not come
  29.          * in picture and multiply(*) will be evaluated first and then
  30.          * divison()/. So output will be 80
  31.          */
  33.         System.out.println("Value of M:" + m);
  34.     }
  36. }

Java 中的运算符

让我们分别讨论每个运算符。

赋值（=）和算术运算符（+, -, *, /）的工作方式与其他编程语言相同，因此在此不再赘述。 /和*运算符的优先级高于加法（+）或减法（-）或取模（%）