Java CIS 109 Test 1

1. What will this output?
int i = 10;
int j = 20;
System.out.println("The result of "+j+" division by 2 is "+i+".");

The result of j division by 2 is i.

The result of 20 division by 2 is 10.

The result of10 division by 2 is 20.

None of the above

The given code will output "The result of 20 division by 2 is 10." This is because the code is using the variables `i` and `j` in the `System.out.println()` statement. The value of `j` is 20 and the value of `i` is 10. So when the code is executed, it will print the string "The result of 20 division by 2 is 10."

Explanation

The given code will output "The result of 20 division by 2 is 10." This is because the code is using the variables `i` and `j` in the `System.out.println()` statement. The value of `j` is 20 and the value of `i` is 10. So when the code is executed, it will print the string "The result of 20 division by 2 is 10."

2. What will this output?
System.out.println(4 + 5 * 2);

14

18

None of the above

The * operator has a higher precedence than the plus operator

Explanation

The * operator has a higher precedence than the plus operator

3. What is the return types of the following body of a method
{
double d = 10;
return 3 * d;
}

Int

Long

Double

30.0

None of the above

The return type of the given method is "double" because the method is declared to return a value of type "double" and the expression "3 * d" evaluates to a double value.

Explanation

The return type of the given method is "double" because the method is declared to return a value of type "double" and the expression "3 * d" evaluates to a double value.

4. Which is the correct boolean expression which gives the following meaning:
The value of x is greater than 1000 and x is smaller or equal to 2000

X >= 1000 && x

X > 1000 && x < 2000

X < 1000 && x >= 2000

X > 1000 && x

None of the above

The correct boolean expression is "x > 1000 && x

Explanation

The correct boolean expression is "x > 1000 && x

5. What will be the output of the following program
class A
{
   public static void main(String[] args)
   {
      System.out.println(getWelcomeMessage());
   }

   static String getWelcomeMessage()
   {
      return "Welcome!!!";
   }
}

GetWelcomeMessage()

GetWelcomeMessage

Welcome!!!

It would give a compilation error

The program will output "Welcome!!!" because the main method calls the getWelcomeMessage() method, which returns the string "Welcome!!!" and then prints it using the System.out.println() method.

Explanation

The program will output "Welcome!!!" because the main method calls the getWelcomeMessage() method, which returns the string "Welcome!!!" and then prints it using the System.out.println() method.

6. What will the following output on the screen?
for (int i = 0; i < 5; i++)
{
System.out.print("*");
}

*****

******

None of the above

It will only output 5 stars one after the other on the same line, because print is being used and not println. The counter i starts from 0, then it will execute the body of the for loop while i is less than 5. It would have output 6 stars if it was i

Explanation

It will only output 5 stars one after the other on the same line, because print is being used and not println. The counter i starts from 0, then it will execute the body of the for loop while i is less than 5. It would have output 6 stars if it was i

7. What is the return types of the following body of a method
{
int i = 10;
return 3 * i;
}

Int

Long

Double

30

None of the above

The return type of the given method body is "int" because the method is declared to return an integer value. The body of the method initializes an integer variable "i" with a value of 10 and then returns the result of multiplying 3 with "i", which is an integer value. Therefore, the correct answer is "int".

Explanation

The return type of the given method body is "int" because the method is declared to return an integer value. The body of the method initializes an integer variable "i" with a value of 10 and then returns the result of multiplying 3 with "i", which is an integer value. Therefore, the correct answer is "int".

8. Will the following compile?
int i = 0;
for (    ; i < 5 ;   )
{
   System.out.println(i);
   i++;
}

Yes

No

The for loops consists of
for (; ; )
All of these are optional and you can leave any of them out. Try experimenting it on BlueJ.

Explanation

The for loops consists of
for (; ; )
All of these are optional and you can leave any of them out. Try experimenting it on BlueJ.

9. What is the return types of the following body of a method
{
return "test "+123;
}

Int

Char

String

Test123

Will not compile

The return type of the given method is String because the body of the method is returning a string value "test "+123. The return statement is used to return a value from a method, and in this case, the value being returned is a string.

Explanation

The return type of the given method is String because the body of the method is returning a string value "test "+123. The return statement is used to return a value from a method, and in this case, the value being returned is a string.

10. Will this compile?
class A
{
System.out.println(20 * 10);
}

Yes

No

No it won't because such a statement should be within some method, e.g. the main method.

Explanation

No it won't because such a statement should be within some method, e.g. the main method.

11. What will this output?
System.out.println(5/2);

2

2.5

Some kind of error

3

Since you are dividing two integers, the result is also an integer. It simply doesn't output the decimal part of the result. If you wanted to show a decimal number, one of them needs to be a double. E.g. 3/2.0

Explanation

Since you are dividing two integers, the result is also an integer. It simply doesn't output the decimal part of the result. If you wanted to show a decimal number, one of them needs to be a double. E.g. 3/2.0

12. Will this compile?
class B
{
   public static void main(String[] args)
   {
      Scanner sc = new Scanner(System.in);
   }
}

Yes

No

No, because you need to import java.util.Scanner

Explanation

No, because you need to import java.util.Scanner