10+ Aon Interview Questions and Answers

Create an ArrayList and add 5 numbers to it.

• Declare an ArrayList variable and initialize it

• Use the add() method to add numbers to the ArrayList

• Numbers can be of any data type (int, double, etc.)

• Example: ArrayList numbers = new ArrayList<>(); numbers.add(1);

• Make sure to import the ArrayList class

HashMap in Java is internally stored as an array of linked lists.

• HashMap uses hashing to store key-value pairs

• Each key is hashed to an index in the array

• If there are collisions, a linked list is used to store multiple values at the same index

• The default initial capacity of HashMap is 16 and load factor is 0.75

• HashMap is not thread-safe and requires synchronization for concurrent access

Implement Push Function for Queue using Array or ArrayList

• Create a function that takes an array or ArrayList and a string as input

• Add the string to the end of the array or ArrayList

• Return the updated array or ArrayList

Explanation of OOPS pillars with real-life examples

• Abstraction: Hiding implementation details, e.g. using a TV remote without knowing how it works

• Encapsulation: Grouping related data and functions, e.g. a car's engine and transmission

• Inheritance: Creating new classes from existing ones, e.g. a sports car class inheriting from a car class

• Polymorphism: Using a single interface to represent multiple classes, e.g. a shape class with different subclasses for circle, square, etc.

I implemented various features including X, Y, and Z.

• Implemented feature X which improved system performance by 20%

• Developed feature Y which allowed for real-time data analysis

• Added feature Z which improved user experience by simplifying the interface

Overloading and overriding are two concepts in object-oriented programming that allow methods to have multiple implementations.

• Overloading is when a class has multiple methods with the same name but different parameters.

• Overriding is when a subclass provides a different implementation of a method that is already defined in its superclass.

• Overloading is resolved at compile-time while overriding is resolved at runtime.

• Example of overloading: public void print(int x) and public ...read more

Print Fibonacci series

• Fibonacci series is a sequence of numbers where each number is the sum of the two preceding ones

• The first two numbers of the series are always 0 and 1

• The series can be generated using a loop or recursion

• Example: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181

Test cases for automation should be selected based on criteria such as frequency of execution, complexity, and criticality.

• Select test cases that are executed frequently to save time and effort.

• Choose test cases that are complex and require multiple steps to execute.

• Prioritize test cases that cover critical functionalities or high-risk areas.

• Consider test cases that involve integration between different systems or modules.

• Include test cases that have a high probability of fai...read more

This program counts the number of repeating characters in a given string.

• Iterate through each character in the string

• Use a hash map to store the count of each character

• If a character is already present in the hash map, increment its count

• Finally, iterate through the hash map and print the characters with their counts

Test cases for automation should be selected based on their frequency of execution, complexity, and stability.

• Identify frequently executed test cases

• Select test cases with high complexity

• Choose stable test cases

• Consider test cases with high risk and impact

• Prioritize regression test cases

• Evaluate the feasibility of automating the test case

Copy a binary tree with a friend node linking to a random node.

• Create a new node for each node in the original tree

• Copy the value of the original node to the new node

• Link the new node to the corresponding node in the new tree

• Generate a random number to select a random node in the new tree

• Link the friend node of each node in the new tree to the randomly selected node