This document contains sample questions and explanations for the OCP Java SE 8 exam related to generics and collections. It includes multiple choice questions testing knowledge of using generics with collections like List and LinkedList, default sorting behavior, and filtering streams. The explanations provide concise technical details about how and why each answer is correct.

1. OCP Java SE 8 Exam
Sample Questions
Generics and Collec.ons
Hari Kiran & S G Ganesh

2. Ques.on
Choose the correct op.on based on this program:
import java.u-l.*;
class U-li-esTest {
public sta-c void main(String []args) {
List<int> intList = new ArrayList<>();
intList.add(10);
intList.add(20);
System.out.println("The list is: " + intList);
}
}
A. It prints the following: The list is: [10, 20]
B. It prints the following: The list is: [20, 10]
C. It results in a compiler error
D. It results in a run-me excep-on
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3. Answer
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Choose the correct op.on based on this program:
import java.u-l.*;
class U-li-esTest {
public sta-c void main(String []args) {
List<int> intList = new ArrayList<>();
intList.add(10);
intList.add(20);
System.out.println("The list is: " + intList);
}
}
A. It prints the following: The list is: [10, 20]
B. It prints the following: The list is: [20, 10]
C. It results in a compiler error
D. It results in a run-me excep-on

4. Explana.on
C. It results in a compiler error
You cannot specify primi-ve types along with generics, so
List<int> needs to be changed to List<Integer>.
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5. Ques.on
Choose the correct op.on based on this program:
import java.u-l.*;
class U-li-esTest {
public sta-c void main(String []args) {
List<Integer> intList = new LinkedList<>();
List<Double> dblList = new LinkedList<>();
System.out.println("First type: " + intList.getClass());
System.out.println("Second type:" + dblList.getClass());
}
}
A. It prints the following:
First type: class java.u-l.LinkedList
Second type:class java.u-l.LinkedList
B. It prints the following:
First type: class java.u-l.LinkedList<Integer>
Second type:class java.u-l.LinkedList<Double>
C. It results in a compiler error
D. It results in a run-me excep-on
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6. Answer
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Choose the correct op.on based on this program:
import java.u-l.*;
class U-li-esTest {
public sta-c void main(String []args) {
List<Integer> intList = new LinkedList<>();
List<Double> dblList = new LinkedList<>();
System.out.println("First type: " + intList.getClass());
System.out.println("Second type:" + dblList.getClass());
}
}
A. It prints the following:
First type: class java.u.l.LinkedList
Second type:class java.u.l.LinkedList
B. It prints the following:
First type: class java.u-l.LinkedList<Integer>
Second type:class java.u-l.LinkedList<Double>
C. It results in a compiler error
D. It results in a run-me excep-on

7. Explana.on
A. It prints the following:
First type: class java.u-l.LinkedList
Second type:class java.u-l.LinkedList
Due to type erasure, aYer compila-on both types are treated
as same LinkedList type.
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8. Ques.on
Choose the correct op.on based on this program:
import java.u-l.Arrays;
class DefaultSorter {
public sta-c void main(String[] args) {
String[] brics = {"Brazil", "Russia", "India", "China"};
Arrays.sort(brics, null); // LINE A
for(String country : brics) {
System.out.print(country + " ");
}
}
}
A. This program will result in a compiler error in line marked with comment
LINE A
B. When executed, the program prints the following: Brazil Russia India China
C. When executed, the program prints the following: Brazil China India Russia
D. When executed, the program prints the following: Russia India China Brazil
E. When executed, the program throws a run-me excep-on of
NullPointerExcep-on when execu-ng the line marked with comment LINE A
F. When executed, the program throws a run-me excep-on of
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9. Answer
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Choose the correct op.on based on this program:
import java.u-l.Arrays;
class DefaultSorter {
public sta-c void main(String[] args) {
String[] brics = {"Brazil", "Russia", "India", "China"};
Arrays.sort(brics, null); // LINE A
for(String country : brics) {
System.out.print(country + " ");
}
}
}
A. This program will result in a compiler error in line marked with comment
LINE A
B. When executed, the program prints the following: Brazil Russia India China
C. When executed, the program prints the following: Brazil China India Russia
D. When executed, the program prints the following: Russia India China Brazil
E. When executed, the program throws a run-me excep-on of
NullPointerExcep-on when execu-ng the line marked with comment LINE A
F. When executed, the program throws a run-me excep-on of

10. Explana.on
C. When executed, the program prints the following: Brazil
China India Russia
When null is passed as a second argument to the Arrays.sort()
method, it means that the default Comparable (i.e., natural
ordering for the elements) should be used. The default
Comparator results in sor-ng the elements in ascending
order. The program does not result in a NullPointerExcep-on
or any other excep-ons or a compiler error.
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11. Ques.on
Choose the correct op.on based on this code segment:
"abracadabra".chars().dis-nct().peek(ch -> System. out .prinb("%c ",
ch)).sorted();
A. It prints: “a b c d r”
B. It prints: “a b r c d”
C. It crashes by throwing a java.u-l.IllegalFormatConversionExcep-on
D. This program terminates normally without prin-ng any output in the
console
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12. Answer
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Choose the correct op.on based on this code segment:
"abracadabra".chars().dis-nct().peek(ch -> System. out .prinb("%c ",
ch)).sorted();
A. It prints: “a b c d r”
B. It prints: “a b r c d”
C. It crashes by throwing a java.u-l.IllegalFormatConversionExcep-on
D. This program terminates normally without prin.ng any output in the
console

13. Explana.on
D. This program terminates normally without prin-ng any
output in the console
A stream pipeline is lazily evaluated. Since there is no
terminal opera-on provided (such as count, forEach,
reduce, or collect), this pipeline is not evaluated and hence
the peek does not print any output to the console.
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14. Ques.on
Choose the correct op.on based on this program:
class Consonants {
private sta-c boolean removeVowels(int c) {
switch(c) {
case 'a': case 'e': case 'i': case 'o': case 'u': return true;
}
return false;
}
public sta-c void main(String []args) {
"avada kedavra".chars()
.filter(Consonants::removeVovels)
.forEach(ch -> System.out.prinb("%c", ch));
}
}
A. This program results in a compiler error
B. This program prints: "aaaeaa"
C. This program prints: "vd kdvr"
D. This program prints: " avada kedavra "
E. This program crashes by throwing a java.u-l.IllegalFormatConversionExcep-on
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15. Answer
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Choose the correct op.on based on this program:
class Consonants {
private sta-c boolean removeVowels(int c) {
switch(c) {
case 'a': case 'e': case 'i': case 'o': case 'u': return true;
}
return false;
}
public sta-c void main(String []args) {
"avada kedavra".chars()
.filter(Consonants::removeVovels)
.forEach(ch -> System.out.prinb("%c", ch));
}
}
A. This program results in a compiler error
B. This program prints: "aaaeaa"
C. This program prints: "vd kdvr"
D. This program prints: " avada kedavra "
E. This program crashes by throwing a java.u-l.IllegalFormatConversionExcep-on

16. Explana.on
B. This program prints: “aaaeaa”
Because the Consonants::removeVowels returns true when
there is a vowel passed, only those characters are retained
in the stream by the filter method. Hence, this program
prints “aaaeaa”.
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