Analyst Integration Interview Preparation Guide

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In HashMap it takes O(1) time, in binary tree it takes O(logN) where N is number of nodes in tree and in linked list it takes O(n) time where n is number of element in list. Millions of records doesn't affect the performance if data structure are working as expected e.g. HashMap has no or relatively less number of collision or binary tree is balanced. If that's not the case then their performance degrades as number of records grows.

Overriding is resolved at runtime while overloading is compile time. Also rules of overriding and overloading is different, for example in Java, method signature of overloaded method must be different than original method, but in case of overriding it must be exactly same as overriding method.

When you fork a process, the new process will run same code as parent process but in different memory space, but when you spawn a new thread in existing process, it just creates another independent path of execution but share same memory space.

critical section is the part of a code, which is very important and in multi-threading must be exclusively modified by any thread. Semaphore or mutex is used to protect critical section. In Java you can use synchronized keyword or ReentrantLock to protect a critical section.

A value type is more optimized type and always immutable e.g. primitive int, long, double and float in Java, while a reference type points to a object, which can be mutable or Immutable. You can also say that value type points to a value while reference type points to an object.

They are two separate areas of memory in same process. Talking about Java, stack is used to store primitive values and reference type to object but actual object is always created in heap. One critical difference between heap and stack is that, heap memory is shared by all threads but each thread has their own stack.

Version control are software which is used to store code and manage versions of codebase e.g. SVN, CVS, Git, Perforce and ClearCase. They are very effective while comparing code, reviewing code and creating build from previous stable version. All professional development use some sort of revision or version control tool, without it you cannot mange code effectively, especially if 20 developers are working in same code base at same time. Version control tool plays very important role to keep code base consistent and resolving code conflicts.

In a strongly typed language compiler ensure type correctness, for example you can not store number in String or vice-versa. Java is a strongly typed language, that's why you have different data types e.g. int, float, String, char, boolean etc. You can only store compatible values in respective types. On the other hand, weakly typed language don't enforce type checking at compile time and they tree values based upon context. Python and Perl are two popular example of weakly typed programming language, where you can store a numeric string in number type.

DOM parser is a in memory parser so it loads whole XML file in memory and create a DOM tree to parse. SAX parser is a event based parser, so it parses XML document based upon event received e.g. opening tag, closing tag, start of attribute or end of attribute. Because of their working methodology, DOM parser is not suitable for large XML file as they will take lot of space in memory and your process may ran out of memory, SAX is the one which should be used to parse large files. For small files, DOM is usually much faster than SAX.

A process can have multiple threads but a thread always belongs to a single process. Two process cannot share memory space until they are purposefully doing inter process communication via shared memory but two threads from same process always share same memory.