Frontend Developer

Write a JS program to implement memoization using closures.
Explanation :- 
Step1: To solve a memoization problem, we need to use the closure.
Step2: The inner function remembers the data in the variable which is declared in the scope of outer function.
Step3: Write the logic for caching the data for 2 cases. 
One for calling a callback function & storing the result in the outer variable & other case for accessing the stored data in that variable.

Write a program to implement polyfill for map function in javascript.
Explanation :-
Step1: Write a check whether that function is available already or not?
Step2: Once above step is done, then write logic to loop over the array on which map is supposed to be applied & call the callback function to get the result & return it. 
Step3: Make sure you handle logic using "this" properly.

Write a program to implement throttling & debouncing in JS?
Approach :-
Step1: Write a utility function to handle throttling logic. we can leverage a closure concept here. 
Step2: Add a flag variable in outer function scope & make it by default true. 
Step3: In the inner function, place a if check & write logic to call the callback function & make flag as false.
Step4: Turn the flag as true after the timeout period.
Step5: Repeat similar logic for debouncing but slightly alter it instead of flag & replace with timer.

1. Why do you want to join Visa?
2. How will you differentiate from others in the team?
3. Tell me a scenario where you have a conflict with your colleague & how you resolved it?
4. Explain a scenario where you have gone extra mile??
5. What would you do differently if you are replaced in place of your boss?