COP3252 Chapter 1 - 4

Question 1

T or F

Information in the memory unit is persistent-it is retained when the copmuter’s power is turned off

Answer 1

False

Question 2

What does a compiler do?

Answer 2

A compiler translates high-level languages like java into machine language.

Question 3

What is unified modelling language (UML)

Answer 3

UML is a graphical language used to represent a software system.

Question 4

Object-oriented design

Answer 4

used to model software in terms of objects

Question 5

How are comments represented in Java?

Answer 5

using (//)

Question 6

What command is used to compile a Java class file?

Answer 6

javac file.java

Question 7

Given the existence of a file named MyClass.class what does the following command do:

java MyClass

Answer 7

This command executes the main file in MyClass.

Question 8

A _______ enables a program to read data from the user.

Answer 8

Scanner

Question 9

Which of the following is not a valid Java primitive type?

double
char
byte
real

Answer 9

real

Question 10

Attributes of a class are known as

Answer 10

Local Variables

Question 11

Which class provides prebuilt dialog boxes that enable programs to display windows containing messages (such windows are called message dialogs)?

Answer 11

JOptionPane

Question 12

What is output by the following Java code segment?
int temp = 200;

if ( temp > 90 )
System.out.println( “This porridge is too hot.” );

if ( temp < 70 )
System.out.println( “This porridge is too cold.” );

if ( temp == 80 )
System.out.println( “This porridge is just right!” );

Answer 12

The porridge is too hot

Question 13

What is output by the following Java code segment?
int temp = 180;

while ( temp != 80 ) 
{
   if ( temp > 90 ) 
   {
      System.out.print( "This porridge is too hot! " );

      // cool down
      temp = temp – ( temp > 150 ? 100 : 20 ); 
   } // end if
   else 
   {
      if ( temp < 70 ) 
      {
         System.out.print(
            "This porridge is too cold! ");

            // warm up
            temp = temp + (temp < 50 ? 30 : 20);
      } // end if
   } // end else
} // end while

if ( temp == 80 )
System.out.println( “This porridge is just right!” );

Answer 13

This porridge is too hot! This porridge is just right!

Question 14

How many times is the body of the loop below executed?
int counter = 1;

while ( counter > 20 ) 
{
   // body of loop
   counter = counter - 1;
} // end while

Answer 14

0