public class Day3 {
public static void main(String[] args) {
//int a =1,b=2,c=3;
int a = 1;
int b = 2;
String name = "长伟";
char x = 'S';
double num = 3.14;
import java.sql.SQLOutput;
public class Day4 {
//类变量 static
static double salary = 2500;
//常量 final
//修饰符,不存在先后顺序
static final double pi = 3.14;
//属性:变量
//实例变量:从属于对象;
String name;
int age;
//main方法
public static void main(String[] args) {
//局部变量;必须声明和初始化值,0 0.0 u0000
//布尔值:默认是false
//除了基本类型,其余默认值都是null
int i = 10;
System.out.println(i);
//变量类型 变量名字 = new Day4();
Day4 day4 = new Day4();
System.out.println(day4.age);
System.out.println(day4.name);
//类变量 static
System.out.println(salary);
//常量
System.out.println(pi);
}
//其他方法
public void add(){
}
}