Review Questions

4.8	Which one of these is a valid method declaration? Select the one correct answer. `void method1 { /* ... / }` `void method2() { / ... / }` `void method3(void) { / ... / }` `method4() { / ... / }` `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. `i = this.planets;` `i = this.suns;` `this = new ThisUsage();` `this.i = 4;` `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. The first pair of methods will compile correctly and overload the method name `fly`. The second pair of methods will compile correctly and overload the method name `fall`. The third pair of methods will compile correctly and overload the method name `glide`. The second pair of methods will not compile correctly. 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. `Book(Book b) {}` `Book Book() {}` `private final Book() {}` `void Book() {}` `public static void Book(String[] args) {}` `abstract Book() {}`
4.12	Which statements are true? Select the two correct answers. All classes must define a constructor. A constructor can be declared `private`. A constructor can return a value. A constructor must initialize all the fields of a class. 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. A compilation error will occur at (1), since constructors cannot specify a return value. A compilation error will occur at (2), since the class does not have a default constructor. A compilation error will occur at (3), since the class does not have a constructor which takes one argument of type `int`. The program will compile correctly.