enumeration javascript code example

Example 1: javascript enumerate

const foobar = ['A', 'B', 'C'];

for (const [index, element] of foobar.entries()) {
  console.log(index, element);
}

Example 2: javascript enum

const seasons = {
  SUMMER: {
    BEGINNING: "summer.beginning",
    ENDING: "summer.ending"
  },
  WINTER: "winter",
  SPRING: "spring",
  AUTUMN: "autumn"
};

let season = seasons.SUMMER.BEGINNING;

if (!season) {
  throw new Error("Season is not defined");
}

switch (season) {
  case seasons.SUMMER.BEGINNING:
  // Do something for summer beginning
  case seasons.SUMMER.ENDING:
  // Do something for summer ending
  case seasons.SUMMER:
  // This will work if season = seasons.SUMMER
  // Do something for summer (generic)
  case seasons.WINTER:
  //Do something for winter
  case seasons.SPRING:
  //Do something for spring
  case seasons.AUTUMN:
  //Do something for autumn
}

Example 3: enum javascript

const DaysEnum = {"monday":1, "tuesday":2, "wednesday":3, ...}
Object.freeze(DaysEnum)

Example 4: javascript enumerators

array.every(elm,index,array) // Did all elements satisfy the callback?
array.find(elm,index,array) // Find the first element that satisfies the callback
array.findIndex(elm,index,array) // Find the first element that satisfies the callback's index
array.map(elm,index,array) // Transform every element and create a new array
array.reduce(accumulator,elm,index,array) // Reduce every element into a new value
array.some(elm,index,array) // Did any element satisfy the callback?