基本算术运算符:
- 加减乘除:+ - * / (java 中的除法是整除;计算中有小数,结果一定是小数)
- 取模运算符: % (只看余数,只有对整数取模,才有“余数”概念)
Public class Demo{
Public static void main(String[] args){
System.out.println(100 + 20); //120
int x = 10;
int y = 20;
System.out.println(x *y); //200
//整除
int m = 10;
double n = 3.0
System.out.println(m/n); //3.0
System.out.println(m%n); //1
}
}
字符串的连接: + (对字符串来说,并不是相加,而是连接的意思。任何数据类型和字符串相连,结果一定是字符串。字符串相连的时候要注意先后顺序,从左向右顺序。小括号可改变优先级)
//连接符号+
String str1 = “Hello”;
String str2 = str1 + “World”;
System.out.println(str2); //HelloWorld
String str3 =”Hello” + 30;
System.out.println(str3); //Hello30
str1 = “Hello” + (10+20); //Hello30
str2 = “Hello” + 10+20; //Hello1020