1、Choose the three valid identifiers from those listed below. (Choose three)?
A. IDoLikeTheLongNameClass
B. $byte
C. const
D. _ok
E. 3_case
答:ABD
2、Which of the following lines of code will compile without error (Choose two)?
A.
int i=0;
if (i) {
System.out.println(“Hi”);
}
B.
boolean b=true;
boolean b2=true;
if(b==b2) {
System.out.println(“So true”);
}
C.
int i=1;
int j=2;
if(i==1|| j==2)
System.out.println(“OK”);
D.
int i=1;
int j=2;
if (i==1 &| j==2)
System.out.println(“OK”);
答:BC
3、Which two demonstrate a "has a" relationship(Choose two)?
A. public interface Person { }
public class Employee extends Person{ }
B. public interface Shape { }
public interface Rectandle extends Shape { }
C. public interface Colorable { }
public class Shape implements Colorable
{ }
D. public class Species{ }
public class Animal{private Species species;}
E. interface Component{ }
class Container implements Component{
private Component[] children;
}
答:DE
4、What will happen when you attempt to compile and run the following code?
public class Static{
static {
int x = 5;
}
static int x,y;
public static void main(String args[]){
x--;
myMethod();
System.out.println(x + y + ++x);
}
public static void myMethod(){
y = x+++++x;
}
}
A.compiletime error
B.prints: 1
C.prints: 2
D.prints: 3
E.prints: 7
F.prints: 8
A答:D
5、What is the correct ordering for the import, class and package
declarations when found in a single file?
A. package, import, class
B. class, import, package
C. import, package, class
D. package, class, import
答:A
6、What will happen when you attempt to compile and run the following code.
public class Pvf{
static boolean Paddy;
public static void main(String argv[]){
System.out.println(Paddy);
}
}
A. Compile time error B. compilation and output of false
C. compilation and output of true D. compilation and output of null 答:B
7、Given the folowing classes which of the following will compile without error?
interface IFace{}
class CFace implements IFace{}
class Base{}
public class ObRef extends Base{
public static void main(String argv[]){
ObRef ob = new ObRef();
Base b = new Base();
Object o1 = new Object();
IFace o2 = new CFace();
}
}
A. o1=o2; B. b=ob; C. ob=b; D. o1=b;
答:ABD
8、下面那幾個(gè)函數(shù)是public void method(){...}的重載函數(shù)?
A)public void method( int m){...} B)public int method(){...}
C)public void method2(){...} D)public int method(int m,float f ){...} 答:AD
9、給出如下聲明:
String s = “Example”;
合法的代碼有哪些?
A)s>>>=3 B)s[3]= “X” C)int i = s.length() D)s = s + 10 答:CD
10、如下哪些不是java的關(guān)鍵字?
A)const B)NULL C) false D)this E) native
答:B
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