Table of contents

1. MDN Docs
2. New Map
   1. From Object
   2. From Mapped Array
   3. Combine 2 maps

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MDN Docs

The Map object holds key-value pairs and remembers the original insertion order of the keys. Any value (both objects and primitive values) may be
used as either a key or a value.

• Demo

  const map1 = new Map();
  map1.set("a", 1);
  map1.set("b", 2);
  map1.set("c", 3);
  
  console.log(map1.get("a"));
  // Expected output: 1
  
  map1.set("a", 97);
  
  console.log(map1.get("a"));
  // Expected output: 97
  
  console.log(map1.size);
  // Expected output: 3
  
  map1.delete("b");
  
  console.log(map1.size);
  // Expected output: 2
  

New Map

From Object

new Map(Object.entries(advancedFields));

From Mapped Array

new Map(data.map((result) => [result.id, `${result.firstName}${result?.middleName && result?.middleName.trim()
                                                               ? ` ${result?.middleName}`
                                                               : ""} ${result.lastName}`,]),);

Combine 2 maps

new Map(choiceArrays.map(...).flat().map(...[key, value]))

• create a map in the format {enumKey: readableString} for choices
  this is es5 to work in Edge and IE

  const enumKeyMap = [].concat
    .apply(
      [],
      choiceArrays.map((choiceArray) => choiceArray.choices),
    )
    .reduce((map, obj) => {
      map[obj.enumKey] = obj.readableString;
      return map;
    }, {});