Fullstack Developer

What is the output of below-console

let x = 18; 
let y = 20; 
console.log("total = "+ x + y);

What is the output of below-console

const arr = [1, 'q', 3); 
arr.map((num) => num*2); 
console.log(arr);

Write a JavaScript function to achieve the output below (should modify the original array).

Input:var obj=[{id:1, name:"john"), (id:2,name: "doe"}]:

output: obj=[{id:1, value:"john"), (id:2, value:"doe"}];

Write a JavaScript function to count and remove all vowels from a string:

Input: str "javascript"

Output: jvscrpt

Write a function that counts how many different characters appear more than once in a string. For instance Input: "ab cd ef a" Output: 1 (the character 'a' appears more than once) 

Input: "abbacdde" Output 3 (the characters 'a', 'b', and 'd' each appears more than once)

Write a function to generate a JWT in Node.js using the JSON web token package. Use userld as the payload.

Write a Node.js function that reads a file asynchronously and prints its contents to the console. Use Promises instead of callbacks.

Write a middleware function in Express.js that logs the method, URL, and response time for each request.

Ques 9. Construct a MongoDB query to perform a join between two collections, Customers and Orders.

Collection: Customers

{"_id": ObjectId("1"), "name": "John Doe", "email": "john@example.com"}

Collection: Orders {"_id": ObjectId("a"), "product": "Laptop", "customerld": Objectid("1")}