Section 4 Quiz 2 - L3-L5
(Answer all questions in this section)
1. What is the output of the following code?
public static void main(String args[]) {
String firstString = "Java";
firstString = firstString.concat("World");
System.out.println(firstString);
} Mark for Review
(1) Points
World
JavaWorld (*)
Java
Java World
Correct Correct
2. String objects are immutable. Mark for Review
(1) Points
True (*)
False
Incorrect Incorrect. Refer to Section 4 Lesson 3.
3. What is the output?
public static void main(String args[]) {
String greeting = "Java World!";
String w = greeting.replace("a", "A");
System.out.println(w);
} Mark for Review
(1) Points
JAvA World! (*)
JavA World!
Java World!
JAva World!
Correct Correct
4. The String class must be imported using java.lang.String; Mark
for Review
(1) Points
True
False (*)
Incorrect Incorrect. Refer to Section 4 Lesson 3.
5. The replaceFirst() method replaces only the first occurrence of
matching character pattern in a string. Mark for Review
(1) Points
True (*)
False
Correct Correct
Section 4 Quiz 2 - L3-L5
(Answer all questions in this section)
6. The indexOf() method returns the index value of a character in
the string. Mark for Review
(1) Points
True (*)
False
Correct Correct
7. A String is a sequence characters. Mark for Review
(1) Points
True (*)
False
Correct Correct
8. Using the Random class requires an import statement. Mark for
Review
(1) Points
True (*)
False
Correct Correct
9. You need to generate random integer values in the range 2 through
10. This code fragment will produce the desired result.
Random r = new Random();
r.nextInt(9) + 2; Mark for Review
(1) Points
True (*)
False
Incorrect Incorrect. Refer to Section 4 Lesson 4.
10. Which class is used to generate random numbers? Mark for Review
(1) Points
Double
Random (*)
Number
Integer
Correct Correct
11. Which values are returned by the method nextBoolean(); Mark for Review
(1) Points
An integer value.
Either a true or false. (*)
Returns the next value.
Nothing is returned.
Correct Correct
12. Which two are the features of the Math class? Mark for Review
(1) Points
(Choose all correct answers)
You don�t have to worry about the data type returned from a Math method.
Common math functions like square root are taken care of in the language. (*)
The Math methods can be invoked without creating an instance of a Math
object. (*)
Math methods can be invoked with Strings as arguments.
Correct Correct
13. All the methods in the Math class are static methods. Mark for
Review
(1) Points
True (*)
False
Correct Correct
14. What is the package name which contains Math class? Mark for
Review
(1) Points
java.lang (*)
java.net
java.io
java.awt
Correct Correct
15. A constant field, like Math.PI is used to represent a fixed
value. Mark for Review
(1) Points
True (*)
False
Correct Correct
