any class
only the Target class
any class in the test package
any class that extends Target
第1题:
使下列程序正常运行并且输出“Hello!”,横线处应填写的内容是( )。 class Test { public static void main(string[]args){ Test t=new Test; start; } Public void run{ System.out.println("Hello!¨); )
A.extends Thread
B.extends Float
C.extends Iostream
D.extends Stdio
第2题:
下列哪个选项的java源文件程序段是不正确的? ( )
A.package testpackage; public class Test{ }
B.import java.io.*; package testpackage; public class Test{ }
C.import java.i.*; class Person{} public class Test{ }
D.import java.io.*; import java.awt.*; public class Test { }
第3题:
下列程序的输出结果是( )。 public class Test { public static void main (String[] args) { String s="hello"; s.replace ('r','m'); System.out.println(s); } }
A.hello
B.HELLO
C.hemmo
D.HEMMO
第4题:
执行以下代码会输出什么结果?() public class Test { StringgetStr(String s){ return s + “hello”; } public static void main(String arg[]) { Test t= new Test(); System.out.println(t.getStr(“LiLei/n”)); } }
第5题:
class A { public A() { System.out.println(“hello from a”); } } class B extends A { public B () { System.out.println(“hello from b”); super(); } } public class Test { public static void main(String args[]) { A a = new B(); } } What is the result when main is executed?()
第6题:
public class Employee{ private String name; public Employee(String name){ this.name = name; } public void display(){ System.out.print(name); } } public class Manager extends Employee{ private String department; public Manager(String name,String department){ super(name); this.department = department; } public void display(){ System.out.println( super.display()+”,”+department); } } 执行语句new Manager(“smith”,”SALES”)后程序的输出是哪项?()
第7题:
smith
null
SALES
编译错误
第8题:
any class
only the Target class
any class in the test package
any class that extends Target
第9题:
any class
only the Target class
any class in the test package
any class that extends Target
第10题:
any class
only the Target class
any class in the test package
any class that extends Target
第11题:
编译报错
LiLei hello
LiLeihello
无任何输出
第12题:
smith,SALES
null,SALES
smith,null
null,null
第13题:
在下画线处填入代码,使程序正常运行并且输出“Hello!”。
class Test ______ {
public staric void maim (string[] args) {
Test t=new Test();
t.start();
}
public void run() {
System.out.println("Hello!");
}
}
第14题:
下列程序段的输出是( )。 public class Test { public static void main (String args[ ]) { String ss1 = new String("hello"); String ss2 = new String("hello"); System.out.println(ssl == ss2); System.out.println (ssequals(ss2)); } }
A.true, false
B.true, true
C.false, true
D.false, false
第15题:
A. hello
B. hello2
C. 编译报错
D. 运行报错,不能将串与整数相加
第16题:
package test1; public class Test1 { static int x = 42; } package test2; public class Test2 extends test1.Test1 { public static void main(String[] args) { System.out.println(“x = “ + x); } } What is the result?()
第17题:
public class Employee{ private String name; public Employee(String name){ this.name = name; } public String getName(){ return name; } } public class Manager extends Employee{ public Manager(String name){ System.out.println(getName()); } } 执行语句new Manager(“smith”)后程序的输出是哪项?()
第18题:
public class Plant { private String name; public Plant(String name) { this.name = name; } public String getName() { return name; } } public class Tree extends Plant { public void growFruit() { } public void dropLeaves() { } } Which is true?()
第19题:
Compilation fails.
hello from a
hello from b
hello from b hello from a
hello from a hello from b
第20题:
smith
null
编译错误
name
第21题:
x = 0
x = 42
Compilation fails because of an error in line 2 of class Test2.
Compilation fails because of an error in line 3 of class Test1.
Compilation fails because of an error in line 4 of class Test2.
第22题:
The code will compile without changes.
The code will compile if public Tree() { Plant(); } is added to the Tree class.
The code will compile if public Plant() { Tree(); } is added to the Plant class.
The code will compile if public Plant() { this(”fern”); } is added to the Plant class.
The code will compile if public Plant() { Plant(”fern”); } is added to the Plant class.
第23题:
any class
only the Target class
any class in the test package
any class that extends Target
第24题:
smith
null
SALES
编译错误