Java 编程语言提供了执行加法、减法、乘法和除法的运算符。你很有可能会被他们在基础数学方面的同行认出他们。唯一对您来说可能看起来很新的符号是%,它将一个操作数除以另一个操作数并将余数作为结果返回。
操作员 | 描述 |
---|---|
+ | 加法运算符(也用于字符串连接) |
- | 减法运算符 |
* | 乘法运算符 |
/ | 分区运算符 |
% | 余数运算符 |
下面的程序ArithmeticDemo测试算术运算符。
class ArithmeticDemo { public static void main (String[] args) { int result = 1 + 2; // result is now 3 System.out.println("1 + 2 = " + result); int original_result = result; result = result - 1; // result is now 2 System.out.println(original_result + " - 1 = " + result); original_result = result; result = result * 2; // result is now 4 System.out.println(original_result + " * 2 = " + result); original_result = result; result = result / 2; // result is now 2 System.out.println(original_result + " / 2 = " + result); original_result = result; result = result + 8; // result is now 10 System.out.println(original_result + " + 8 = " + result); original_result = result; result = result % 7; // result is now 3 System.out.println(original_result + " % 7 = " + result); } }
该程序打印以下内容:
1 + 2 = 3 3 - 1 = 2 2 * 2 = 4 4 / 2 = 2 2 + 8 = 10 10 % 7 = 3
您还可以将算术运算符与简单赋值运算符结合起来创建复合赋值。例如,x += 1;两者x = x + 1;都将 的值增加x1。
该+运算符还可用于将两个字符串连接(连接)在一起,如以下ConcatDemo程序所示:
class ConcatDemo { public static void main(String[] args){ String firstString = "This is"; String secondString = " a concatenated string."; String thirdString = firstString+secondString; System.out.println(thirdString); } }
在这个程序结束时,变量thirdStringcontains This is a concatenated string.,它被打印到标准输出。