1 public class Demo3 {
2 public static void main(String[] args) {
3 int a = 10;
4 int b = 20;
5
6 a+=b;//a = a + b
7 a-=b;//a = a - b
8 System.out.println(a);
9 //字符串连接符 + ,String
10 System.out.println(""+a+b);//输出1020
11 System.out.println(a+b+"");//输出30
12 }
13 }
1 public class Demo4 {
2 //三元运算符
3 public static void main(String[] args) {
4 //x ? y : z
5 //如果x == true,则结果为y,否则结果为z
6
7 int score = 50;
8 String type = score <60 ? "不及格" : "及格";//必须掌握!!!
9 System.out.println(type);//输出为不及格
10 }
11 }