find the difference of two maps in javascript

To find the difference of two maps in JavaScript, you can iterate over the keys of the first map and check if each key exists in the second map. If the key does not exist in the second map, add it to a new map that will store the difference. Here's an example:

index.tsx
const map1 = new Map([
  ['a', 1],
  ['b', 2],
  ['c', 3]
]);

const map2 = new Map([
  ['b', 4],
  ['c', 3],
  ['d', 5]
]);

const diff = new Map();

for (let [key, value] of map1) {
  if (!map2.has(key)) {
    diff.set(key, value);
  }
}

console.log(diff); // Output: Map { 'a' => 1 }
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In the above example, we have two maps map1 and map2. We want to find the difference of these two maps, which contains the elements that are present in map1 but not in map2.

We create a new map diff to store the result. Then, we loop over the keys of map1 using a for...of loop. For each key-value pair, we check if the key exists in map2 using the has() method. If the key is not present in map2, we add it to the diff map using the set() method.

Finally, we print the diff map, which contains the elements that are only present in map1 and not in map2. In this example, the output is Map { 'a' => 1 }.