package demo;
public class Bianliang {
public static void main(String[] args) {
//定义变量
int a = 10;
//输出变量
System.out.println(a);
//修改变量
a = 20;
System.out.println(a);
}
}

package demo;
public class Bianliang {
public static void main(String[] args) {
//定义变量
int a = 10;
//输出变量
System.out.println(a);
//修改变量
a = 20;
System.out.println(a);
}
}