Microsoft Frontend Engineer Interview Questions

Users in Microsoft Office 365 often face lag in interface responsiveness due to multiple rapid inputs. Implement a debounce function to enhance user experience by limiting the rate of function executions.
Define a method debounce(func, wait) that returns a debounced version of the given function which ensures the function is invoked after a delay only if it hasn't been called within the wait period.Example 1:
Input: const debouncedFunc = debounce(() => console.log('Action'), 1000); debouncedFunc(); (followed by another call within 1 sec)
Output: No output, because the function has not fired due to debouncingConstraints:
- wait is a non-negative integer.
- The debounced function can be called at most 10^6 times.

Microsoft Edge needs to track user actions such as clicks to improve user experience through analytics. Using closures, implement a simple action counter.
The Counter class should support the following methods:
- increment() -> void: Increases the count by 1.
- getCount() -> number: Returns the current count.Example 1:
Input: const counter = new Counter(); counter.increment(); counter.increment(); counter.getCount();
Output: 2
Explanation: The counter was incremented twice, so it returns 2.Constraints:
- The count will never be negative.
- There will be at most 10^6 calls to the methods.

For Azure DevOps, implement a lightweight client-side router that allows navigation between different dashboard components without a full page reload. The Router class should support the following methods:
- addRoute(path: string, handler: Function): void: Adds a new route with its corresponding handler function.
- navigate(path: string): void: Navigates to the specified path and invokes the associated handler.Example 1:
Input: const router = new Router(); router.addRoute('/home', () => console.log('Welcome to Home')); router.navigate('/home');
Output: Welcome to Home
Explanation: Adding a route for /home and then navigating to it triggers the corresponding handler.Constraints:
- At most 100 routes can be added.
- Route paths will always be unique and valid.

To enhance the performance of OneDrive, implement an LRU (Least Recently Used) Cache that stores recently accessed files. The cache should have a maximum size and remove the least recently used file whenever a new file is added beyond that limit.
Define the LRUCache class with the following methods:
- get(fileID: int) -> str: Retrieves the file content for the given file ID and updates its usage.
- put(fileID: int, content: str) -> None: Stores the file content in the cache. If the cache exceeds the size, remove the least recently used file.Example 1:
Input: const lruCache = new LRUCache(2); lruCache.put(1, 'File1'); lruCache.put(2, 'File2'); lruCache.get(1);
Output: 'File1'
Explanation: Accessing file 1 keeps it in the cache while file 2 is also stored.Constraints:
- Cache size will be at most 3000 files.
- Each fileID will be unique.