I have across a block of code that I couldn't really tackle. It is written as following:

function getValue (callback) {
  setTimeout(() => {
    callback("B")
  }, 10)
} 

How can we call this function to return the string, "B" as it has a callback inside a timeout of 10ms. Any help? I have tried calling it normally but it returns undefined. Can anyone explain how this block of code works?

--Here is the problem that was supposed to be solved. There are three functions that return A,B,C respectively as strings and the goal here is to get the output to be printed the same as above (A,B,C).

function getA () {
  return "A"
} 

const getB = async () => { const b = await "B"; return b }

function getC (callback) {
  setTimeout(() => {
  callback("C")
  })
}