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18. A class design requires that a member variable should be accessible only by same package, which modifer word should be used?
A. protected
B. public
C. no modifer
D. private
19.Which declares for native method in a java class corrected?
A. public native void method(){}
B. public native void method();
C. public native method();
D. public void method(){native;}
E. public void native method();
20. Which modifer should be applied to a declaration of a class member variable for the value of variable to remain constant after the creation of the object?
16-20答安：
16。B
静态方法除了自己的参数外只能直接访问静态成员。访问非静态成员，必须先实例化本类的一个实例，再用实例名点取。
17。A、B、D
polygon的顶点信息存放在Vector类型的对象内部，color定义为Color，length和width定义为int。
注意，这是考试中常见的题型。
18。C
此题考点是高级访问控制。请考生查阅高级访问控制说明表格。
19。B
native关键字指明是对本地方法的调用，在JAVA中是只能访问但不能写的方法，它的位置在访问权限修饰语的后面及返回值的前面。
20。final
定义常量的方法是在变量定义前加final关键字。
21. Which is the main() method return of a application?
A. String
B. byte
C. char
D. void
22. Which is corrected argument of main() method of application?
A. String args
B. String ar[]
C. Char args[][]
D. StringBuffer arg[]
23. “The Employee object is a person, An Employee has appointment store in a vector, a hire date and a number of dependent”
short answer: use shortest statement declare a class of Employee.
24. Give the following class defination inseparate source files:
public class Example{
public Example(){//do something}
protected Example(int i){//do something}
protected void method(){//do something}
}
public class Hello extends Example{//member met上一页 [1] [2] [3] [4] [5] [6] [7] 下一页 |
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