Apex Infotech Interview Questions and Answers

The problem involves finding the maximum profit that can be achieved by buying and selling stocks on different days.

• Iterate through the array of stock prices and find the local minima and maxima to calculate profit

• Keep track of the total profit by adding the differences between consecutive maxima and minima

• You can perform multiple transactions, so buy at each local minima and sell at each local maxima

• Example: For prices = [7, 1, 5, 3, 6, 4], buy at 1, sell at 5, buy at 3, sel...read more

Abstract classes and interfaces in inheritance allow for defining common behavior and function signatures, while function overloading and overriding enable polymorphism.

• Abstract classes are classes that cannot be instantiated and may contain abstract methods that must be implemented by subclasses.

• Interfaces are similar to abstract classes but can only contain method signatures and constants, with no method implementations.

• Function overloading refers to having multiple methods...read more

Asynchronous functions in JavaScript allow code to run without blocking other code from executing.

• Asynchronous functions use callbacks or promises to handle the result of the function.

• They are useful for tasks that may take a long time to complete, such as fetching data from a server.

• Examples include setTimeout(), fetch(), and XMLHttpRequest().

Polymorphism is the ability of an object to take on many forms.

• It allows objects of different classes to be treated as if they were objects of the same class.

• It is achieved through method overriding and method overloading.

• Example: A parent class Animal can have child classes like Dog, Cat, and Cow. All of them have a common method called 'makeSound', but each of them makes a different sound.

• Example: A method can be overloaded by having the same name but different parameters, ...read more

Reverse alternate words in a given string

• Split the string into words

• Reverse alternate words using a loop

• Join the words back into a string

Use a hashmap to store the frequency of each letter in the given string.

• Iterate through the string and update the frequency of each letter in the hashmap.

• Return the hashmap containing the frequency of each letter.