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单项选择题X 纠错

Given：

What is the result？（）

A.Compilation fails.
B.Cannot add Toppings
C.The code runs with no output.
D.A NullPointerException is thrown in Line 4.

参考答案：

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单项选择题

A team of programmers is involved in reviewing a proposed design for a new utility class. After some discussion， they realize that the current design allows other classes to access methods in the utility class that should be accessible only to methods within the utility class itself.
What design issue has the team discovered？（）

A.Tight coupling
B.Low cohesion
C.High cohesion
D.Loose coupling
E.Weak encapsulation
F.Strong encapsulation

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多项选择题

Given：

Which two code fragments， inserted independently at line 13， will compile？（）

A.super（name， baseSalary）；
B.this.commission = commission；
C.super（）； this.commission = commission；
D.this.commission = commission； super（）；
E.super（name， baseSalary）； this.commission = commission；

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多项选择题

Given：

What are four valid examples of polymorphic method calls？（）

A.x.a2（）；
B.z.a2（）；
C.z.c1（）；
D.z.a1（）；
E.y.c1（）；
F.x.a1（）；

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单项选择题

Given:

What is the result？（）

A.peep
B.bark
C.meow
D.Compilation fails.
E.An exception is thrown at runtime.

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单项选择题

Given：

Which change can you make to Target without affecting Client？（）

A.Line 4 of class Target can be changed to return i++；
B.Line 2 of class Target can be changed to private int i = 1；
C.Line 3 of class Target can be changed to private int addOne（）{
D.Line 2 of class Target can be changed to private Integer i = 0；

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单项选择题

Given a method that must ensure that its parameter is not null：
11. public void someMethod（Object value） {
12. // check for null value
...
20. System.out.println（value.getClass（））；
21. }
What inserted at line 12， is the appropriate way to handle a null value？（）

A.assert value == null；
B.assert value != null， "value is null"；
C.if （value == null） { throw new AssertionException（"value is null"）； }
D.if （value == null） { throw new IllegalArgumentException（"value is null"）； }

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单项选择题

A team of programmers is involved in reviewing a proposed design for a new utility class. After some discussion， they realize that the current design allows other classes to access methods in the utility class that should be accessible only to methods within the utility class itself.
What design issue has the team discovered？（）

A.Tight coupling
B.Low cohesion
C.High cohesion
D.Loose coupling
E.Weak encapsulation

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单项选择题

Given：
11.double input = 314159.26；
12.NumberFormat nf = NumberFormat.getInstance（Locale.ITALIAN）；
13.String b；
14.//insert code here
Which code， inserted at line 14， sets the value of b to 314.159，26？（）

A.b = nf.parse（ input ）；
B.b = nf.format（ input ）；
C.b = nf.equals（ input ）；
D.b = nf.parseObject（ input ）；

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单项选择题

Given：

If an instance of class Beagle is created，then Serialized，then deSerialized， what is the result？（）

A.ad
B.ada
C.add
D.adad

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单项选择题

Given：
11.String test = "This is a test"；
12.String[] tokens = test.split（"\s"）；
13.System.out.println（tokens.length）；
What is the result？（）

A.0
B.1
C.4
D.Compilation fails.

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