1. What does array.map() do?
Array.map() calls a function for each element in an array and returns a new array.
2. What does array.reduce() do?
Array.reduce() takes an accumulator and a value. The value of each array element is tested against a function. whatever value the function returns is stored in the accumulator and by the end of the process, the array has been reduced down to a single value which can be returned as a string, array or an object.
3.Code snippets for how to us superagent() to fetch data from a URL and log result
Normal Promise using .then()
superagent.get(urlHere)
.then(dataFromUrl=>{
console.log(dataFromUrl.body)
})
Using async/await
async function getData(){
let urlData = await superagent.get(urlHere)
console.log(urlData.body)
}
getData();
4. What are promises?
A promise can be stated explicitly or implicitly. The code which the promise depends on can either resolve or reject the promise.
5. Are callback functions considered to be Asynchronous
Not all callback function are asynchronous because some callbacks can be called as regular functions while an async function is a reference/argument from another function that will run and when finished will allow the function it was passed through to complete. source