Java测试试卷.doc

JAVA测试试卷 (2007年)一、选择题（每题3分，共30分）1、关于JAVA程序的构成及存储要求，下列说法中正确的是 (C )。(A) JAVA程序由一个或多个public类构成，存盘时文件名必须以其中一个public类的类名命名。(B) JAVA程序必须包含一个public类，存盘时文件名必须以public类的类名命名。(C) JAVA程序最多包含一个public类，若有public类，则存盘时文件名必须以public类的类名命名，否则以其他任何一个类的类名命名即可。(D) JAVA程序由一个或多个public类构成，存盘时文件名以程序中任何一个类的类名命名即可。2、下列代码编译后不会出现警告或错误的是 ( B )。(A) char c = a; (B) byte b = 255; (C) float c = 10.0; (D) double d = 1.0f;3、下面这段代码编译时会发生什么情况( A )。public class MyClass public static void main(String args) amethod(args);public void amethod(String args) System.out.println(args);System.out.println(args1);(A) error, cant make static reference to void amethod(B) error, method main not correct(C) error, array must include parameter (D) amethod must be declared with String4、执行下述命令的输出结果为 ( D)。java myprog good morningpublic class myprog public static void main(String args) System.out.println(args2);(A) myprog (B) good (C) morning (D) Exception raised: java.lang.ArrayIndexOutOfBoundsException: 25、下列关于数组的声明与创建语句中，正确的是( C )。(A) int a10; a= new int10; (B) float b10 = new float ;(C) char c = new char10; (D) byte b10; b = new byte ;6、下述程序的输出结果为 ( A )。class Cal private int x, y, z; int cal() z = x*y; return z; public class exam public static void main(String args) Cal tmp = new Cal(); tmp.x = 10; tmp.y = 20; System.out.print(tmp.cal(); (A) 私有变量访问错误，不能通过编译 (B) 200 (C) 30 (D) 107、下述程序正确的是( D )。(A) public class A public static void main(String args) short snum1, snum2, snum3; snum1 = 10; snum2 = 20; snum3 = snum1 + snum2;/类型转换 (B) public class B_1 public void method() public class B_2 extends B_1private void method() /继承问题(C) public class C public int method() return 0;public String method() return “neu”;/函数重载(D) public class D public static void main(String args) final int a = 100; final int b; b = 200;8、下述程序的输出结果为 ( D )。class Cube public int length; public static int width, height; Cube() length = width = height = 10; void setValue(int length, int width, int height) this.length = length; this.width = width; this.height = height; public class StaValue public static void main(String args) Cube v1 = new Cube(); Cube v2 = new Cube(); Cube v3 = new Cube(); v2.setValue(20, 20, 20); v3.setValue(30, 30, 30); System.out.println(v1.length + + v2.width + + v3.height); (A) 10 20 30 (B) 30 30 30 (C) 20 20 30 (D) 10 30 309、下述程序的输出结果为 ( B )。public class StringTest public static void main(String args) String s1 = new String (we are students); String s2 = new String (we are students); String s3 = new String (This example is about substring); String s4 = new String (); s4 = s3.substring(5, 14); System.out.print(s1.length(); System.out.print(s1= =s2); System.out.print(s2.indexOf(are); System.out.print(s4); (A) 16 false 3 example is (B) 15 false 3 example i(C) 15 true 4 example i (D) 16 true 4 example is10. 下面这段代码编译和运行时会发生什么情况 ( C )。abstract class MineBase abstract void amethod();static int i;public class Mine extends MineBase public static void main(String args) int ar = new int5;for(int i=0; i ar.length; i+)System.out.println(ari);(A) 将0到4打印出来 (B) Error: ar is used before it is initialized (C) Error: Mine is not abstract and does not override abstract method amethod () in MineBase(D) Array IndexOutOfBoundes Error二、填空题（每题3分，共30分）1、设jdk已安装至C盘的jdk1.5.0目录，则Windows系统的环境变量PATH应设为_ C:jdk1.5.0bin ，CLASSPATH应设为_ C:jdk1.5.0lib _。JAVA源程序文件的扩展名为_.java_，编译后生成的字节码文件的扩展名为_.class_。2、下述程序的输出结果为 _23_。public class ScopeTest public int i = 1;public void firstMethod() int i = 7, j = 8;this.i = i + j;secondMethod(this.i);public void secondMethod(int i) int j = 8;this.i = i + j;public static void main(String args) ScopeTest obj = new ScopeTest(); obj.firstMethod(); System.out.println(obj.i);3、下述程序的输出结果为 _39_。class MathTwo static int add(int a, int b) return a + b; static int sub(int a, int b) return a - b; static int mul(int a, int b) return a * b; public class MathTwoTest public static void main(String args) int x = 8, y = 5, z; z = MathTwo.mul(MathTwo.add(x, y), MathTwo.sub(x, y); System.out.print(z); 4、下述程序的输出结果为_1981-12-10_。public class MyDatepublic int year;public int month;public int day;public MyDate(int y, int m, int d) year = y; month = m; day = d; public void setYear(int y) year = y; public void setMonth(int m) month = m; public void setDay(int d) day = d;public class ChangeDate public static void changeDate_1(MyDate mydate) mydate = new MyDate(1979, 2, 3); public static void changeDate_2(MyDate mydate) mydate.setMonth(12); public static void main(String args) MyDate date = new MyDate(1981, 9, 10); changeDate_1(date); changeDate_2(date); System.out.println(date.year + “-“ + date.month + “-“ + date.day);5、下述程序的输出结果为_8000_。class Cube int length=10, width=20, height=30;Cube() length = width = height = 20; public void setValue(int length, int width, int height) this.length = length; this.width = width; this.height = height; public int volume() return length * width * height; public class CubeInstance public static void main(String args) Cube v1 = new Cube(); System.out.print(v1.volume(); 6、下述程序的输出结果为_ Invocation child class _。public class OverridingParent public void method() System.out.println(Invocation parent class);public class OverridingChild extends OverridingParentpublic void method() System.out.println(Invocation child class);public static void main(String args) OverridingChild t = new OverridingChild();t.method();7、下述程序的输出结果为_ Child getInfo invoked _。class Parent public String getInfo() return “Parent getInfo invoked”;class Child extends Parent public String getInfo() return “Child getInfo invoked”;public class VirtualMethod public static void main(String args) Parent p = new Child(); System.out.println(p.getInfo(); 8、下述程序的输出结果为_1977-8-16_。public class ParentConstructor public int year; public int month; public int day; public static final int default_month = 2; public static final int default_day = 16; public ParentConstructor(int y, int m, int d) year = y; month = m; day = d; public ParentConstructor(int y) this(y, default_month, default_day); public ParentConstructor(int y, int m) this(y, m, default_day); public class ChildConstructor extends ParentConstructor public ChildConstructor(int h) super(1977, 8); public static void main(String args) ChildConstructor t = new ChildConstructor(12); System.out.println(t.year + - + t.month + - + t.day); 9、下述程序的输出结果为_false false false true_。public class EqualsTest public static void main(String args) MyDate day1 = new MyDate(3, 2, 2002); MyDate day2 = new MyDate(3, 2, 2002); System.out.println(day1 = = day2); System.out.println(day1.equals(day2); String str1 = new String(A String); String str2 = new String(A String); System.out.println(str1 = = str2); System.out.println(str1.equals(str2); 10、下述程序的输出结果为_30 10 20_。class A int i, j; void setA(int i, int j) this.i = i; this.j = j; class B extends A int j, k; void setB(i