public class Main {

public static void main(String [ ] args) {

string[ ] furnitures={"Door","Window","Chair"};

var sb= new StringBuilder( );

for (var i =0; i < furnitures. length; i++){

var index =i +1;

sb .append (i)

 .append(").")

 .append (furnitures [i]. charAt (i))

 .append(",");

 if (index< furnitures. length){

 sb. append (" | ");

 }

}

sb. delete(sb. length () -2, sb. length( ) -1);

sb.insert (0, '[') insert(sb. length( )-1, " ] " );

System. out.printIn(sb);

 }

}

结果如何?

/proj/msg/messages. properties file:

message=Hello {0), regards {1}

and

/proj/msg/messages_ja_JP. properties file:

message=c(0),一段日文,{1}

and

/proj/msg/Test. java class:

pakage msg;

public class Test {

public static void main(String[ ] args) {

// line 1

System. out. printIn(message);

}

}

You want to print the message 一段日文,Jane.

插入到第1行中的哪段代码可以完成这个任务?  

public class FileHandler{

public static void main(String[ ] args) {

try (FileInputstream in =new FileInputstream("foo. txt")){ }

// line 1

 }

}

可以在第1行插入哪个代码片段来编译代码?  

enum Role {

TL (10), ML(10), DEVELOPER (20);

int weight =100;

private Role (int weight){

 this. weight = weight;

 }

}

and the code fragment

public class App {

public static void main(String [ ] args){

Set<Role> roles = new Treeset<>( );

roles. add(Role. ML);

roles. add(Role.TL);

roles. add(Role. DEVELOPER);

for (Role r: roles) {

System.out.printIn(r.weight + " "+ r);

 }

 }

}

结果如何?

public class Main {

public static void main(String... args){

List<string> list1 = new Arraylist<>(

List. of ("Earth", "Wind", "Fire") );

List<String> list2 = List. copyof (list1);

list1. sort ((String item1, String item2)-> item1. compareTo(item2));

list2. sort ((String item1 String item2)-> item1. compareTo(item2));

System. out.printIn(list2. equals (list1));

 }

}

结果如何?

List<Integer> list = List.of(11, 12, 13,12, 13);

哪个语句导致编译时错误?

6. public class Test {

7. private string s ="private reset";

8. private int var1;

9. private int var2;

10. static {

11. varl =1;

12. }

13. public static void main(String[ ] args) {

14. Test test= new Test( );

15. test.s = "Private reset";

16. System.out.printIn(test.s +" "+ var1 + var2);

17. }

18. }

您必须采取哪些操作才能编译此代码?

public class A {

 private string name;

 public String getName () {

 return name;

 }

 public void setName(String name){

 this. name =name;

 }

 public String tostring(){

 return getName ()；

 }

}

and

public class B extends A{

 public void setName (String name){

 super. setName("\""+ name + "\"");

 }

 public void setName (String... nameParts) {

 var output = format (nameParts);

 setName(output);

 }

 private String format(String... parts) {

 var sb= new StringBuilder();

 for(string part: parts) { sb. append (part). append (' '); }

 return sb. tostring ();

 }

 public static void main(String... args) {

 A a =new B ( );

 a. setName (args);

 }

}

为什么编译失败?

1. public class Main {

2. public static void greet (String... args) {

3. System. out.print ("Hello ") ;

4. for (String arg : args) {

5. System.out.println(arg) ;

6. }

7. }

8. public static void main (String[] args) {

9. Main C = null;

10. c.greet() ;

11. }

12. }

结果如何?

public class Test{

 private static class Greet{

 private void print(){

 System.out.println("Hello world");

 }

 }

 public static void main(String[] args) {

 Test.Greet i=new Greet();

 i.print();

 }

}

结果如何?

public class Calculator{

public static void main(String... args) {

MyInterface myInterface =a->a+1;

System. out.println (myInterface.add(10)) ;

}

}

interface MyInterface {

int add(int x) ;

}

哪个接口来自java. util. 函数包可以用来重构计算器类? 

public enum Status {

BRONZE(5) ,SILVER(10)，GOLD(15) ;

private int rate;

private Status (int rate) {

this.rate = rate;

}

public int getRate () { return rate; }

public Status addstatus (int rate) {

return new Status (20) ;

}

}

and

public class Test {

public static void main(String[] args) {

Status silver = Status .SILVER;

System.out.printIn(silver+silver.getRate()) ;

Status platinum = Status.addstatus (20) ;

System. out .println (platinum+platinum. getRate()) ;

}

}

结果如何?

public class Employee{

private String name ;

private String neighborhood;

private LocalDate birthday;

private int salary;

}

and

List<Employee> roster = new ArrayList<>(...) ;

Map<String, Optional <Employee>> m = roster.stream()

// Line 1

第1行中的哪个代码片段使m映射包含每个社区中工资最高的员工?  

public class Test {

public static void main(string[] args) {

AnotherClass ac = new AnotherClass () ;

SomeClass sc = new AnotherClass() ;

ac = SC;

sC. methodA() ;

ac. methodA() ;

}

}

class SomeClass {

public void methodA() {

System. out. println ("SomeClassi#methodA() ") ;

}

}

class AnotherClass extends SomeClass{

public void methodA(){

System . out.println ("AnotherClass#methodA()") ;

}

}

结果如何?

public class DNASynth {

int aCount; :

int tCountp

int cCount;

int gCount;

DNASynth(int a, int tCount, int C, int g) {

// line 1

}

int setccount (int c) {

return C;

}

void setGCount (int gCount) {

this.gCount = gCount;

}

}

哪两行代码在插入到第一行时正确地修改了实例变量?  （答案存疑）

package test.t1;

public class A {

public int x = 42;

protected A() { } // line 1

}

and

package test. t2;

import test. t1.*;

public class B extends A {

int X= 17; // line 2

public B() { super() ; } // line 3

}

and

package test;

import test.t1.*;

import test.t2. *;

public class Tester {

public static void main(String [ ] args) {

Aobj=newB(); // line 4

System.out.println(obj.x); // line 5

}

}

结果如何?

public class Foo {

public static String ALPHA = "alpha";

protected String beta ="beta";

private final String delta;

public Foo(String d) {

delta = ALPHA + d;

}

public String foo() {

return beta+= delta;

}

}

哪个改变会使Foo更安全?