True or False 1)Suppose you have the following declaration: int xyz = 4; Then, i

Question

True or False

1)Suppose you have the following declaration: int xyz = 4; Then, in the body of a switch statement block

case xyz: System.out.println(“4”);
break;
is legal.

2)A variable declared as static cannot ever be modified, once it has been declared and initialized.

3)Consider the statement: throw new IllegalArgumentException(); This always causes the program to immediately exit.

4)If a non abstract class A implements interface B, class A does not have to define all the methods in interface B. But if it doesn't class A cannot be instantiated.

5)The binary search algorithm will work properly on all integer arrays.

6)The declaration FilledOval[ ][ ] A = new FilledOval[20][30]; creates 600 FilledOval instances using the FilledOval() constuctor.

Explanation / Answer

1) Suppose you have the following declaration:

int xyz = 4; Then, in the body of a switch statement block

case xyz: System.out.println(“4”);

break;

is legal. ------------------------ > False

Explanation: this is illegal; because case expressions must be constant expressions.

2) A variable declared as static cannot ever be modified, once it has been declared and initialized.

-------------------> False

Explanation: static variables can be modified.

3) Consider the statement: throw new IllegalArgumentException(); This always causes the program to immediately exit. -------------------> False

Explanation: this would not cause the program to immediately exit; the exception can be caught in catch block and error message can be printed after that.

4)If a non abstract class A implements interface B, class A does not have to define all the methods in interface B. But if it doesn't class A cannot be instantiated. -------------------> True

Explanation: when A implements interface B either A has to implement all the methods of B or A should be declared as abstract class and an abstract class cannot be instantiated.

5)The binary search algorithm will work properly on all integer arrays. -------------------> False

Explanation: binary search algorithm will work only for sorted arrays whether it is an integer array or a float array that does not matter but array must be sorted for this to work properly.

6)The declaration FilledOval[ ][ ] A = new FilledOval[20][30]; creates 600 FilledOval instances using the

FilledOval() constructor. -------------------> True

Explanation: FilledOval[ ][ ] A = new FilledOval[20][30]; this declaration would create 600 instances of FilledOval class and by default it uses FilledOval() constructor.

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