Review Questions


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4.8

Which one of these is a valid method declaration?

Select the one correct answer.

  1. void method1 { /* ... */ }

  2. void method2() { /* ... */ }

  3. void method3(void) { /* ... */ }

  4. method4() { /* ... */ }

  5. method5(void) { /* ... */ }

4.9

Given the following code, which statements can be placed at the indicated position without causing compilation errors?

 public class ThisUsage {     int planets;     static int suns;     public void gaze() {         int i;         // ... insert statements here ...     } } 

Select the three correct answers.

  1. i = this.planets;

  2. i = this.suns;

  3. this = new ThisUsage();

  4. this.i = 4;

  5. this.suns = planets;

4.10

Given the following pairs of method declarations, which statements are true?

 void fly(int distance) {} int  fly(int time, int speed) { return time*speed; } void fall(int time) {} int  fall(int distance) { return distance; } void glide(int time) {} void Glide(int time) {} 

Select the two correct answers.

  1. The first pair of methods will compile correctly and overload the method name fly .

  2. The second pair of methods will compile correctly and overload the method name fall .

  3. The third pair of methods will compile correctly and overload the method name glide .

  4. The second pair of methods will not compile correctly.

  5. The third pair of methods will not compile correctly.

4.11

Given a class named Book , which one of these is a valid constructor declaration for the class?

Select the one correct answer.

  1. Book(Book b) {}

  2. Book Book() {}

  3. private final Book() {}

  4. void Book() {}

  5. public static void Book(String[] args) {}

  6. abstract Book() {}

4.12

Which statements are true?

Select the two correct answers.

  1. All classes must define a constructor.

  2. A constructor can be declared private .

  3. A constructor can return a value.

  4. A constructor must initialize all the fields of a class.

  5. A constructor can access the non-static members of a class.

4.13

What will be the result of attempting to compile the following program?

 public class MyClass {     long var;     public void MyClass(long param) { var = param; }  // (1)     public static void main(String[] args) {         MyClass a, b;         a = new MyClass();                            // (2)         b = new MyClass(5);                           // (3)     } } 

Select the one correct answer.

  1. A compilation error will occur at (1), since constructors cannot specify a return value.

  2. A compilation error will occur at (2), since the class does not have a default constructor.

  3. A compilation error will occur at (3), since the class does not have a constructor which takes one argument of type int .

  4. The program will compile correctly.



A Programmer[ap]s Guide to Java Certification
A Programmer[ap]s Guide to Java Certification
ISBN: 201596148
EAN: N/A
Year: 2003
Pages: 284

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