思遷數(shù)碼科技Java軟件工程師筆試題和面試題答案

選擇題

　　1:Which statements about Java code security are not true?

　　A.The bytecode verifier loads all classes needed for the execution of a program.

　　B.Executing code is performed by the runtime interpreter.

　　C.At runtime the bytecodes are loaded, checked and run in an interpreter.

　　D.The class loader adds security by separating the namespaces for the classes of the local file system from those imported from network sources.

　　2:What is the result when you compile and run the following code?

　　public class Test

　　{

　　public void method()

　　{

　　for(int i = 0; i < 3; i++)

　　{

　　System.out.print(i);

　　}

　　System.out.print(i);

　　}

　　}

　　Choices:

　　What is the result when you compile and run the following code?

　　public class Test

　　{

　　public void method()

　　{

　　for(int i = 0; i < 3; i++)

　　{

　　System.out.print(i);

　　}

　　System.out.print(i);

　　}

　　}

　　Choices:

　　A.0122

　　B.0123

　　C.Compilation error

　　D.None of these

　　3:

　　Give the following code:

　　public class Example{

　　public static void main(String args[] ){

　　int l=0;

　　do{

　　System.out.println(“Doing it for l is:”+l);

　　}while(--l>0)

　　System.out.println(“Finish”);

　　}

　　}

　　Which well be output:

　　Give the following code:

　　public class Example{

　　public static void main(String args[] ){

　　int l=0;

　　do{

　　System.out.println(“Doing it for l is:”+l);

　　}while(--l>0)

　　System.out.println(“Finish”);

　　}

　　}

　　Which well be output:

　　A.Doing it for l is 3

　　B.Doing it for l is 1

　　C.Doing it for l is 2

　　D.Doing it for l is 0

　　4:Math.round(11.5)等於多少?

　　A.11

　　B.12

　　C.11.5

　　D.none

　　5:

　　What will happen when you attempt to compile and run the following code?

　　int Output = 10;

　　boolean b1 = false;

　　if((b1 == true) && ((Output += 10) == 20))

　　{

　　System.out.println("We are equal " + Output);

　　}

　　else

　　{

　　System.out.println("Not equal! " + Output);

　　}

　　Choices:

　　What will happen when you attempt to compile and run the following code?

　　int Output = 10;

　　boolean b1 = false;

　　if((b1 == true) && ((Output += 10) == 20))

　　{

　　System.out.println("We are equal " + Output);

　　}

　　else

　　{

　　System.out.println("Not equal! " + Output);

　　}

　　Choices:

　　A.Compilation error, attempting to perform binary comparison on logical data type

　　B.Compilation and output of "We are equal 10".

　　C.Compilation and output of "Not equal! 20".

　　D.Compilation and output of "Not equal! 10".

　　6:

　　What will happen when you attempt to compile and run the following code?

　　(Assume that the code is compiled and run with assertions enabled.)

　　public class AssertTest{

　　public void methodA(int i){

　　assert i >= 0 : methodB();

　　System.out.println(i);

　　}

　　public void methodB(){

　　System.out.println("The value must not be negative");

　　}

　　public static void main(String args[]){

　　AssertTest test = new AssertTest();

　　test.methodA(-10);

　　}

　　}

　　What will happen when you attempt to compile and run the following code?

　　(Assume that the code is compiled and run with assertions enabled.)

　　public class AssertTest{

　　public void methodA(int i){

　　assert i >= 0 : methodB();

　　System.out.println(i);

　　}

　　public void methodB(){

　　System.out.println("The value must not be negative");

　　}

　　public static void main(String args[]){

　　AssertTest test = new AssertTest();

　　test.methodA(-10);

　　}

　　}

　　A.it will print -10

　　B.it will result in AssertionError showing the message-“the value must not be negative”.