10 Tips to Help You Stand Out as a Java Developer | by John Selawsky | Mar, 2021 | Better Programming
https://betterprogramming.pub/10-tips-to-help-you-stand-out-as-a-java-developer-9865516584ae
https://betterprogramming.pub/10-tips-to-help-you-stand-out-as-a-java-developer-9865516584ae
Medium
10 Tips to Help You Stand Out as a Java Developer
What you need to know to master Java
Java String Interview Questions
=======================
1) Is String a keyword in Java?
2) Is String a primitive type or derived type?
3) In how many ways you can create string objects in Java?
4) What is string constant pool?
5) What is special about string objects as compared to objects of other derived types?
6) What do you mean by mutable and immutable objects?
7) Which is the final class in these three classes – String, StringBuffer and StringBuilder?
8) What is the difference between String, StringBuffer and StringBuilder?
9) Why StringBuffer and StringBuilder classes are introduced in Java when there already exist String class to represent the set of characters?
10) How many objects will be created in the following code and where they will be stored in the memory?
String s1 = "abc";
String s2 = "abc";
11) How do you create mutable string objects?
12) Which one will you prefer among “==” and equals() method to compare two string objects?
13) Which class do you recommend among String, StringBuffer and StringBuilder classes if I want mutable and thread safe objects?
14) How do you convert given string to char array?
15) How many objects will be created in the following code and where they will be stored?
String s1 = new String("abc");
String s2 = "abc";
16) Where exactly string constant pool is located in the memory?
17) I am performing lots of string concatenation and string modification in my code. which class among string, StringBuffer and StringBuilder improves the performance of my code. Remember I also want thread safe code?
18) What is string intern?
19) What is the main difference between Java strings and C, C++ strings?
20) How many objects will be created in the following code and where they will be stored?
String s1 = new String("abc");
String s2 = new String("abc");
21) Can we call String class methods using string literals?
22) do you have any idea why strings have been made immutable in Java?
23) What do you think about string constant pool? Why they have provided this pool as we can store string objects in the heap memory itself?
24) What is the similarity and difference between String and StringBuffer class?
25) What is the similarity and difference between StringBuffer and StringBuilder class?
26) How do you count the number of occurrences of each character in a string?
27) How do you remove all white spaces from a string in Java?
28) How do you find duplicate characters in a string?
29) Write a Java program to reverse a string?
30) Write a Java program to check whether two strings are anagram or not?
31) Write a Java program to reverse a given string with preserving the position of spaces?
32) How do you convert string to integer and integer to string in Java?
33) Write a code to prove that strings are immutable in Java?
34) Write a code to check whether one string is a rotation of another?
35) Write a Java program to reverse each word of a given string?
36) Print all substrings of a string in Java?
37) Print common characters between two strings in alphabetical order in Java?
38) How find maximum occurring character in a string in Java?
39) What is difference between Java 8 StringJoiner, String.join() and Collectors.joining()?
40) How to reverse a sentence word by word in Java?
=======================
1) Is String a keyword in Java?
2) Is String a primitive type or derived type?
3) In how many ways you can create string objects in Java?
4) What is string constant pool?
5) What is special about string objects as compared to objects of other derived types?
6) What do you mean by mutable and immutable objects?
7) Which is the final class in these three classes – String, StringBuffer and StringBuilder?
8) What is the difference between String, StringBuffer and StringBuilder?
9) Why StringBuffer and StringBuilder classes are introduced in Java when there already exist String class to represent the set of characters?
10) How many objects will be created in the following code and where they will be stored in the memory?
String s1 = "abc";
String s2 = "abc";
11) How do you create mutable string objects?
12) Which one will you prefer among “==” and equals() method to compare two string objects?
13) Which class do you recommend among String, StringBuffer and StringBuilder classes if I want mutable and thread safe objects?
14) How do you convert given string to char array?
15) How many objects will be created in the following code and where they will be stored?
String s1 = new String("abc");
String s2 = "abc";
16) Where exactly string constant pool is located in the memory?
17) I am performing lots of string concatenation and string modification in my code. which class among string, StringBuffer and StringBuilder improves the performance of my code. Remember I also want thread safe code?
18) What is string intern?
19) What is the main difference between Java strings and C, C++ strings?
20) How many objects will be created in the following code and where they will be stored?
String s1 = new String("abc");
String s2 = new String("abc");
21) Can we call String class methods using string literals?
22) do you have any idea why strings have been made immutable in Java?
23) What do you think about string constant pool? Why they have provided this pool as we can store string objects in the heap memory itself?
24) What is the similarity and difference between String and StringBuffer class?
25) What is the similarity and difference between StringBuffer and StringBuilder class?
26) How do you count the number of occurrences of each character in a string?
27) How do you remove all white spaces from a string in Java?
28) How do you find duplicate characters in a string?
29) Write a Java program to reverse a string?
30) Write a Java program to check whether two strings are anagram or not?
31) Write a Java program to reverse a given string with preserving the position of spaces?
32) How do you convert string to integer and integer to string in Java?
33) Write a code to prove that strings are immutable in Java?
34) Write a code to check whether one string is a rotation of another?
35) Write a Java program to reverse each word of a given string?
36) Print all substrings of a string in Java?
37) Print common characters between two strings in alphabetical order in Java?
38) How find maximum occurring character in a string in Java?
39) What is difference between Java 8 StringJoiner, String.join() and Collectors.joining()?
40) How to reverse a sentence word by word in Java?
Where is an array stored into the memory?
Anonymous Quiz
49%
Heap Space
23%
Stack Space
16%
Heap Space & Stack Space
12%
First generation memory
Which of the following are TCL commands?
Anonymous Quiz
17%
UPDATE & TRUNCATE
30%
SELECT & INSERT
22%
GRANT & REVOKE
31%
ROLLBACK & SAVEPOINT
What does SAM stands for in the context of Functional Interface?
Anonymous Quiz
9%
Single Ambivalue method
77%
Single Abstract Method
0%
Simple active markup
15%
Simple abstract markup
Which component is used to compile, debug and execute a program?
Anonymous Quiz
50%
JVM
31%
JDK
8%
JIT
12%
JRE
How to remove duplicates from List?
Anonymous Quiz
37%
HashSet<String> listToSet = new HashSet<String>(duplicateList);
24%
HashSet<String> listToSet = duplicateList.toSet();
27%
HashSet<String> listToSet = Collections.convertToSet(duplicateList);
12%
HashSet<String> listToSet = duplicateList.getSet();
Which of the following is a correct way of inheriting class A by class B?
Anonymous Quiz
6%
class B + class A{ }
21%
class B inherits class A{ }
49%
class B extends A{ }
25%
class B extends class A{ }
Which of these is super Class of wrappers Double & Integer?
Anonymous Quiz
26%
Long
13%
Digits
26%
Float
36%
Number
which concept of java is a way of converting real world objects in terms of class?
Anonymous Quiz
38%
Polymorphism
16%
Inheritance
22%
Abstraction
25%
Encapsulation
What will be the output of the following code snippet?
class A{ } enum Enums extends A{ ABC,BCD,CDE,DEF; }
class A{ } enum Enums extends A{ ABC,BCD,CDE,DEF; }
Anonymous Quiz
15%
Runtime Error
21%
Compile time Error
34%
It runs successfully
30%
EnumNotDefinedException
What will be the output of the following Java code?
enum Season
{ WINTER, SPRING, SUMMER, FALL }; System.out.println(Season.WINTER.ordinal());
enum Season
{ WINTER, SPRING, SUMMER, FALL }; System.out.println(Season.WINTER.ordinal());
Anonymous Quiz
42%
0
40%
1
17%
2
0%
3
What is the difference between length() and size() of ArrayList?
Anonymous Quiz
19%
length() and size() return the same value
24%
length() is not defined in ArrayList
10%
size() is not defined in ArrayList
47%
length() returns capacity of ArrayList and size() returns actual number of elements stored in list
public class Program
{
public static void main(String[] args) { String s="I LIKE JAVA"; System.out.println(s.charAt(3)); } }
{
public static void main(String[] args) { String s="I LIKE JAVA"; System.out.println(s.charAt(3)); } }
Anonymous Quiz
42%
I
34%
L
22%
K
3%
E
The "all-or-none" property commonly known as
Anonymous Quiz
22%
Isolation
11%
Durability
30%
Atomicity
37%
All the above
When an array is passed to a method, will the content of the array undergo changes with the actions carried within the function?
Anonymous Quiz
70%
True
30%
False
public class VarArgs
{
public static void print(Object... obj){
System.out.println("Object...:"+obj[0]);
}
public static void main(String[] args) {
//(1) Method call here)
}
}
Which Method call, when inserted at (1), will not result in the following output from the program:
Object...: 9
{
public static void print(Object... obj){
System.out.println("Object...:"+obj[0]);
}
public static void main(String[] args) {
//(1) Method call here)
}
}
Which Method call, when inserted at (1), will not result in the following output from the program:
Object...: 9
Given the following declaration, which expression return the size of the array, assuming the array has been initialized? Select the one correct answer.
int[] array;
int[] array;
Anonymous Quiz
24%
array[].length()
14%
array.length()
17%
array[].length
26%
array.length
5%
array[].size()
14%
array.size()