Interview Questions and Answers - Order By Rating Q991. Difference between Eager and Lazy loading in hibernate ? Hibernate
Ans. Lazy Loading is loading of entities on demand when subclass is called, while Eager loading is loading of all the sub entity at the start only.
Eager loading is fast as all sub entities are already present, but its heavy(takes more memory) Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q992. Write a program that count the number of access to a method? Core Java
This question was recently asked at 'TrueCaller'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Ans. A weak reference is a reference that gets removed on the next garbage collection cycle. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  weak reference  garbage collection Asked in 1 Companies   rare Q994. What is the programming advantage of Immutability ? Design
This question was recently asked at 'Overstock.com'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  mmutable  immutability  immutabilit Asked in 1 Companies This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q996. What is Test driven development ? Process
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q997. What is the relation between classes in Java ? Core Java
Ans. There are different types of relationship between classes
Inheritance - Also called is-a relationship, Child class object carries the body of the Parent class when initiated. Moreover there are certain privileges attach to method overriding to the classes related this way. This relationship exist for code reuse, method overriding and interfacing ( through abstract class ).
Composition - Also called has-a relationship. Class objects carries a reference to other class objects when instantiated. This relationship exist for work flow / work delegation.
Inner / Nested class - It’s a relationship that encapsulates the inner class or it’s object within the outer class. This relationship exist for encapsulation / security. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q998. What is the difference between implementing interfaces and inheritance in Java ? Core Java
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q999. Can we have a private default method ? Core Java
Ans. No. The whole idea of default method is to provide a default definition in case the implementing class intend to provide definition for only some of the methods. Making any of the interface method private would restrict it from being implemented by the implementing class. So default method is an option to provide implementation and not restricting a new definition. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  default methods Q1000. What could be the reason for allowing private methods in java 9 ? Core Java
Ans. Java 8 allowed for method implementation using default methods in interfaces. As those default methods could contain complex logic and might need organizing the logic into multiple methods, they have allowed for private methods. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  default methods Q1001. Can we have private methods in interfaces ? Core Java
Ans. Yes, With Java 9 Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9Ans. JShell is a feature in java 9 using which we can code and test without compiling using javac and see the result of calculations directly. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  jshell  java 9 Q1003. How Java 9 would help resolve NoClassDefFoundError through it's modularity ? Core Java
Ans. Java 9 would provide an error at compile time if there are different modules with the same package mapped to the same class loader and hence would provide a compile time check for this issue.
NoClassDefFoundError exists because of ambiguity at realtime because of multiple versions of same package / class exist. As Java 9 would provide a compile time check for it through clearly defined dependencies and exports and a check on duplicate packages being loaded by single class loader, it will fix the problem. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java 9 modules Q1004. What is the default setting for Automatic modules regarding exporting packages and reading modules ? Core Java
Ans. As one purpose of automatic module is to provide backward compatibility with the module less dependencies, automatic modules exports all packages and include all other modules. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java 9 modules Q1005. How does Java 9 provides backward compatibility with libraries that haven't published themselves as modules ? Core Java
Ans. Though Automatic modules. Any JAR on the module path without module descriptor ends up as automatic module Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java 9 modules Q1006. How does modularity in Java 9 facilitates better encapsulation ? Core Java
Ans. By providing dependencies , services and exports explicitly Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java 9 modules Q1007. What are the qualified and unqualified packages ? Core Java
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java 9 modules Q1008. Does Java 9 allows same package within different modules ? Core Java
Ans. Yes it allows if the modules are mapped to different class loaders. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java 9 modules Q1009. What is the use of Requires, Exports, Opens and provides within Module Descriptor ? Core Java
Ans. Requires specifies the dependencies for the module, i.e the modules required for this module to function.
Exports specifies the packages exported by the module.
Opens specifies the packages opened by the module.
Provides specifies the services provided by the module
Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java modules   java 9 modules Q1010. Difference between named and unnamed modules ? Core Java
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java modules   java 9 modulesAns. A Module layer is created from a graph of modules and is a function that maps modules to their class loaders. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java modules   java 9 modules This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java modules   java 9 modules Q1013. Do we need different class loaders for different modules in Java 9 ? Core Java
Ans. No, We can use the same class loader. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java modules   java 9 modules Q1014. How Java 9 helps in building light weight applications ? Core Java
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java modules   java 9 modules Q1015. How modules are different than packages in Java 9 ? Core Java
Ans. Modules are independently build units and contains multiple packages. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java modules   java 9 modules Q1016. What is the concept of modules in Java 9 ? Core Java
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java modules   java 9 modules Q1017. Why do we have multiple core java jars in java 9 ? Core Java
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java 9  java modules   java 9 modules Q1018. Why java allows explicit import of class final static elements but not others ? Core Java
Ans. Because they can be replaced easily in pre compilation whereas others cannot. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q1019. What will the following code print and Why
class Class1 {
static{
System.out.println("Wow");
}
public static final int xyz=1;
}
class Class2{
public static void main(String[] args) {
System.out.println(String.valueOf(Class1.xyz));
}
} Core Java
Ans. 1
Reason being that Class1.xyz is replaced with 1 during pre compilation only and a reference to Class1 is never made. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  static final   pre compilation This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve