公共类编号{ publicstaticvoidmain (string [ ] args ) { Computer computer=new Computer ); computer.hp (; }}class Computer { int i1; //全局变量成员变量实例字段,不带赋值的publicvoidHP(({inti2=0; int i3; //没有默认值,并且必须分配值才能使用system.out.println(I1 ),system.out.println(I2 ); system.out.println(I3; //错误,不初始化就不能调用}