The protected Modifier pacakge pI acakge p2 C2是c1 class c class c2 extends C1 的子类 protected intx x can be read or modified in C2 C1和c3 在同 class C3 class C4 个包中 Cl cl CI c.x can be read or clx cannot be rea C4与c1 modified nor modified 不在同 个包 中The protected Modifier pacakge p1 class C1 protected int x class C3 C1 c1; c1.x can be read or modified pacakge p2 class C2 extends C1 x can be read or modified in C2 class C4 C1 c1; c1.x cannot be read nor modified C1和C3 在同一 个包中 C2是C1 的子类 C4与C1 不在同 一个包 中