Java oop預(yù)習(xí)學(xué)習(xí)筆記5(動(dòng)力節(jié)點(diǎn)版)：引用與局部變量的示例代碼
public class OOTest03
{
public? ?static? ?void? ? main(String[ ] args) {
User u = new User() ;/*u是引用? ，u是局部變量*/
//以下為上一個(gè)版本中編寫的
//u.addr = new Address () ;
Address a = new Address () ;
u.addr= a;/*a是引用? ，a是局部變量*/
System. out . print1n (u. addr.city); //null
a.city = "天津";
System. out . println (u. addr.city); //天津
}
}
標(biāo)簽：
