package 數據類型;
//如果一個聲明定義包含一個初始化，那么每次進入聲明它的程序塊時，該變量都要被重新初始化
class LifeTime {
?public static void main(String args[]){
??int x;
??
??for(x = 0; x < 3; x++){
???int y = -1;
???System.out.println("y is: " + y);
???y = 100;
???System.out.println("y is now: " + y);
??}
?}
}