Solution code for Express drills

1. Create a route handler function on the path /sum that accepts two query parameters named a and b and find the sum of the two values. Return a string in the format "The sum of a and b is c". Note that query parameters are always strings so some thought should be given to converting them to numbers.

2. Create an endpoint /cipher. The handler function should accept a query parameter named text and a one named shift. Encrypt the text using a simple shift cipher also known as a Caesar Cipher. It is a simple substitution cipher where each letter is shifted a certain number of places down the alphabet. So if the shift was 1 then A would be replaced by B, and B would be replaced by C and C would be replaced by D and so on until finally Z would be replaced by A. using this scheme encrypt the text with the given shift and return the result to the client.

3. To send an array of values to the server via a query string simply repeat the key with different values. For instance, the query string ?arr=1&arr=2&arr=3 results in the query object { arr: [ '1', '2', '3' ] }. Create a new endpoint /lotto that accepts an array of 6 numbers between 1 and 20. The function then randomly generates 6 numbers between 1 and 20. Compare the numbers sent in the query with the randomly generated numbers to determine how many match. If fewer than 4 numbers match respond with the string "Sorry you lose". If 4 numbers match respond with the string "Congratulations, you win a free ticket", if 5 numbers match respond with "Congratulations! You win $100!". If all 6 numbers match respond with "Wow! Unbelievable! You could have won the mega millions!".