Java exam
Math.pow(4, 1 / 2) returns __________.
1.0
24 % 5 is _____
4
What is x after the following statements? int x = 2; int y = 1; x *= y + 1;
4
What is i printed? public class Test {public static void main(String[] args) { int j = 0; int i = ++j + j * 5; System.out.println("What is i? " + i);}}
6
One byte has ____ bits?
8 bits
is software that interprets Java bytecode
Java virtual machine
Which of the following are not permanent storage devices?
Main memory
____ is a program that runs on a computer to manage and control a computer's activities
Operating System
Analyze the following code.public class Test {public static void main(String[] args) {int month = 09;System.out.println("month is " + month);}
Syntax error 09
Suppose you define a Java class as follows, the source code should be stored in a file named_______. Public class Test { }
Test.java
Analyze the following code:public class Test {public static void main(String[] args) {int n = 10000 * 10000 * 10000;System.out.println("n is " + n);}}
The result of 10000 * 10000 * 10000 is too large to be stored in an int variable.
Which JDK command is correct to run a Java application in Bytecode.class
java Bytecode
The JDK command to compile a class in the file Test.java is
javac Test.java
If a program compiles fine, but it produces incorrect results, then the program suffers______.
logic error
Computer can execute the code in
machine language
Which of the following are the reserved words?
public static void class
The main method header is written as:
public static void main (String []args)
Which of the following is a valid identifier? radius, class, public, 9+10, 7, $5322, 10
radius and $5322
2.11 To assign a value 1 to variable x, you write D. 1 := x; C. x := 1; E. x == 1; B. x = 1; A. 1 = x;
x=1;
____ is not an object-oriented programming language
C#
____is the brain of a computer
CPU
To obtain the current minute, use _________. A. System.currentTimeMillis() % 3600 B. System.currentTimeMillis() % 60 C. System.currentTimeMillis() / 1000 % 60 D. System.currentTimeMillis() / 1000 / 60 % 60 E. System.currentTimeMillis() / 1000 / 60 / 60 % 24
D
To add number to sum, you write (Note: Java is case-sensitive) D. sum += number; B. number = sum + number; A. number += sum; C. sum = Number + sum; E. sum = sum + number;
D E
Which of the following assignment statements is incorrect? A. i = j = k = 1; B. i = 1; j = 1; k = 1; D. i == j == k == 1; C. i = 1 = j = 1 = k = 1;
D and C
Which of the following expressions will yield 0.5? C. (double) (1 / 2) A. 1 / 2 D. (double) 1 / 2 B. 1.0 / 2 E. 1 / 2.0
D,B,E
Which of the following assignment statements is illegal? B. int t = 23; D. int t = (int)false; C. short s = 10; A. float f = -34; E. int t = 4.5;
D,E
____ consists of a set of separate programs for developing and testing Java programs, each of which is invoked from command line
JAVA JDK
_____ is interpreted
Java
____ contains predefined classes and interfaces for developing Java programs
Java API
Are the following four statements equivalent? number += 1; number = number + 1; number++; ++number;
Yes
Why do computers use zeros and ones?
because digital devices have two stable states and it is natural to use one state for 0 and the other for 1.
If you forgot to put a closing quotation mark on string, what kind of error will be raised?
compile error
Which of the following is incorrect? A. int x = 9; B. long x = 9; D. double x = 1.0; C. float x = 1.0;
flox x = 1.0;
Which of the following are correct ways to declare variables? for int length and width
int length, width; int length; int width;