Java Questions

The classloader is a subsystem of JVM that is used to load classes and interfaces.There are many types of classloaders e.g. Bootstrap classloader, Extension classloader, System classloader, Plugin classloader etc.

The purpose of garbage collection is to identify and discard objects that are no longer needed by a program so that their resources can be reclaimed and reused. A Java object is subject to garbage collection when it becomes unreachable to the program in which it is used.

If you need to support random access, without inserting or removing elements from any place other than the end, then ArrayList offers the optimal collection. If, however, you need to frequently add and remove elements from the middle of the list and only access the list elements sequentially, then LinkedList offers the better implementation.

The diamond problem is an ambiguity that can occur when a class multiply inherits from two classes that both descend from a common super class

Encapsulation describes the ability of an object to hide its data and methods from the rest of the world 

Static member class is a class defined inside outer class with static modifier.

EX:

Class A {  //top level class or outer class

    .....

    static class B {  //static member class

    }

   .....

}

Path contains path of .exe files(commands).

Classpath contains path of packages. packages can be stored in folder or .jar files

Function: A Function is a block of statement which perform some operation.

Declaring the function before using the function in program is known as implicit declaration of the function.

For Example::

int bar(void); // function (forward) declaration

int main(void) {

bar(); // bar was declared, the compiler has all the info

return foo(123); // foo not yet known; impl. decl. warning

}

// not previously declared function definition

int foo(int a) {

return a;

} 

// previously declared function definition

int bar() {

return 321;

}