Java Questions

Function is an algorithm which can be used any where in the program when required

If exception is generated  in try and if that exception is not catch by any catch then finally is executed.

If exception is generated in try and if that exception is caught by one of catch statements then also finally is executed.

if no exception is generated then also finally is executed.

A Thread is a block of code that can be executed in parallel with another block of code.

ArrayList and LinkedList both implements List interface and maintains insertion order. Both are non synchronized classes.

But there are many differences between ArrayList and LinkedList classes that are given below.

ArrayList    V/s     LinkedList ::

1) ArrayList internally uses dynamic array to store the elements.

                   Whereas

LinkedList internally uses doubly linked list to store the elements.

2) Manipulation with ArrayList is slow because it internally uses array. If any element is removed from the array, all the bits are shifted in memory.

                   Whereas

Manipulation with LinkedList is faster than ArrayList because it uses doubly linked list so no bit shifting is required in memory.

3) ArrayList class can act as a list only because it implements List only.

                   Whereas

LinkedList class can act as a list and queue both because it implements List and Deque interfaces.

4) ArrayList is better for storing and accessing data.

                   Whereas

LinkedList is better for manipulating data.

There are lots of ways to solve the issue of callback hells:

1. Modularization: break callbacks into independent functions
2. Use a control flow library, like async
3. Use generators with Promises
4. Use async/await (note that it is only available in the latest v7 release and not in the LTS version)

If you mark an instance variable as transient, you're telling the JVM to skip (ignore) this variable when you attempt to serialize the object containing it.