Javascript MapReduce example

map-reduce.js

const map = new Map([[1, true], [2, true], [3, false], [4, false], [5, true]]);

const processedMap = Array.from(map.entries())
  .map(([key, value]) => [value, key])
  .reduce((acc, [key, value]) => acc.set(key, value + (acc.get(key) || 0)), new Map());

console.log('---------- Original Map ----------');
for (const [key, value] of map.entries()) {
  console.log(`key: ${key}, value: ${value}`);
}

console.log('---------- Processed Map ----------');
for (const [key, value] of processedMap.entries()) {
  console.log(`key: ${key}, value: ${value}`);
}