10+ Interview Questions and Answers

Yes, it is possible to work with multiple threads in core data.

• Use NSManagedObjectContextConcurrencyType to specify concurrency type

• Create a separate managed object context for each thread

• Use performBlock or performBlockAndWait to execute tasks on the correct context

• Merge changes from other contexts using NSManagedObjectContextDidSaveNotification

The optimal algorithm for finding common elements in two arrays is using a hash table.

• Create a hash table for one of the arrays.

• Iterate through the other array and check if each element exists in the hash table.

• If it does, add it to the result array.

• Time complexity is O(n) and space complexity is O(n).

Memory leaks occur when a program fails to release memory that is no longer needed.

• Memory leaks can happen due to programming errors such as not freeing allocated memory

• Leaked memory can accumulate over time and cause the program to crash or slow down

• Memory leaks can be detected using tools such as valgrind or by analyzing the program's behavior

• Examples of memory leaks include forgetting to free memory allocated for a variable or not closing a file after reading from it

Java code to filter even numbers from a list and store the square of those in another list

• Create two ArrayLists to store the original list and the squared even numbers list

• Iterate through the original list and check if each number is even

• If the number is even, square it and add it to the squared even numbers list

Threads in Java can be created by extending the Thread class or implementing the Runnable interface.

• Extend the Thread class and override the run() method

• Implement the Runnable interface and implement the run() method

• Use the Executor framework for managing threads

Microcontrollers are integrated circuits designed for specific tasks with built-in memory and peripherals, while microprocessors are general-purpose CPUs without built-in memory or peripherals.

• Microcontrollers are typically used in embedded systems for specific tasks like controlling a microwave oven or a washing machine.

• Microprocessors are used in general-purpose computing devices like laptops, desktops, and servers.

• Microcontrollers have built-in memory and peripherals like ...read more

Java code to check if two strings are anagrams

• Create a function that takes in two strings as parameters

• Convert both strings to char arrays and sort them

• Compare the sorted char arrays to check if they are equal

Stream API in Java provides a functional approach to processing collections of objects.

• Allows for concise and readable code by using functional programming concepts like map, filter, and reduce.

• Enables parallel processing of data, improving performance for large datasets.

• Supports lazy evaluation, allowing for efficient use of resources.

• Example: List names = Arrays.asList("Alice", "Bob", "Charlie"); names.stream().filter(name -> name.startsWith("A")).forEach(System.out::printl...read more

Functional interfaces in Java are needed to enable the use of lambda expressions, which provide a concise way to implement single abstract method interfaces.

• Functional interfaces have exactly one abstract method and can have multiple default or static methods.

• They are used to enable the use of lambda expressions, which provide a concise way to implement the single abstract method.

• Examples of functional interfaces in Java include Runnable, Callable, and ActionListener.

Hardware refers to physical components of a computer, while RAM is a type of hardware that stores data temporarily.

• Hardware includes components such as the CPU, motherboard, and hard drive.

• RAM stands for Random Access Memory and is used to temporarily store data that the computer is currently using.

• Hardware is permanent and cannot be changed without physically replacing the component, while RAM can be upgraded or added to.

• Examples of hardware include a keyboard, mouse, and mo...read more

Promises are used in JavaScript to handle asynchronous operations.

• Promises are objects that represent the eventual completion or failure of an asynchronous operation.

• They are used to handle asynchronous operations in a more readable and manageable way.

• Promises have three states: pending, fulfilled, or rejected.

• They can be chained using .then() and .catch() methods.

• Promises can be created using the Promise constructor or by using the shorthand syntax with async/await.

• Example: ...read more

Array methods in JavaScript are built-in functions that allow manipulation and traversal of arrays.

• Some common array methods include: map(), filter(), reduce(), forEach(), and find().

• map() - creates a new array by applying a function to each element in the original array.

• filter() - creates a new array with elements that pass a certain condition.

• reduce() - applies a function against an accumulator and each element in the array to reduce it to a single value.

• forEach() - execute...read more