Ultramax Infonet Technologies Interview Questions and Answers

Generator functions in JS are special functions that can pause and resume their execution, allowing for asynchronous programming.

• Generator functions are defined using function* syntax.

• They use the yield keyword to pause execution and return a value.

• Generators can be iterated over using a for...of loop or by manually calling the next() method on the generator object.

• They are commonly used for asynchronous programming, allowing for easier handling of asynchronous tasks.

apply, call, and bind are methods used in JavaScript to manipulate the context of a function.

• apply() - calls a function with a given 'this' value and arguments provided as an array

• call() - calls a function with a given 'this' value and arguments provided individually

• bind() - creates a new function that, when called, has its 'this' keyword set to the provided value

Implement a retry function in node.js

• Create a function that takes a function and number of retries as parameters

• Use a loop to call the function and handle errors

• Use setTimeout to delay retries if needed

Indexes in MongoDB can have disadvantages like increased storage space, slower write operations, and potential performance degradation.

• Indexes can take up additional storage space as they store copies of the indexed fields.

• Creating and maintaining indexes can slow down write operations, as the indexes need to be updated whenever the data changes.

• Having too many indexes can lead to performance degradation, as MongoDB has to evaluate multiple indexes to find the optimal query p...read more

Currying is a technique in functional programming where a function with multiple arguments is transformed into a sequence of functions, each taking a single argument.

• Currying helps in creating reusable functions and improving code readability.

• It allows partial application of functions, where some arguments are fixed and others are left to be provided later.

• Example: const add = (a) => (b) => a + b; add(2)(3) will return 5.