maintain order in map js code example

Example 1: javascript map

function listFruits() {
  let fruits = ["apple", "cherry", "pear"]
  
  fruits.map((fruit, index) => {
    console.log(index, fruit)
  })
}

listFruits()

// https://jsfiddle.net/tmoreland/16qfpkgb/3/

Example 2: map in javascript

let myMap = new Map()

let keyString = 'a string'
let keyObj    = {}
// setting the values
myMap.set(keyString, "value associated with 'a string'")
myMap.set(keyObj, 'value associated with keyObj')
myMap.set(keyFunc, 'value associated with keyFunc')
myMap.size              // 3
// getting the values
myMap.get(keyString)    // "value associated with 'a string'"
myMap.get(keyObj)       // "value associated with keyObj"
myMap.get(keyFunc)      // "value associated with keyFunc"