Large ECMAScript Maps compared to Object

map-comparison.js

/*
 * Map
 */
let map = new Map();
console.time('push');
for (let i = 0; i < 100000; i++) {
	map.set(i, i);
}
console.timeEnd('push');

console.time('remove');
for (let i = 0; i < 100000; i++) {
	map.delete(i);
}
console.timeEnd('remove');

for (let i = 0; i < 100000; i++) {
	map.set(i, i);
}

console.time('both same');
for (let i = 0; i < 100000; i++) {
	map.delete(0);
	map.set(0, 0);
}
console.timeEnd('both same');

console.time('both different');
for (let i = 0; i < 100000; i++) {
	map.delete(i % 1000);
	map.set(i % 1000, i % 1000);
}
console.timeEnd('both different');

/*
 * Object
 */
map = Object.create(null);
console.time('push');
for (let i = 0; i < 100000; i++) {
	map[i] = i;
}
console.timeEnd('push');

console.time('remove');
for (let i = 0; i < 100000; i++) {
	delete map[i];
}
console.timeEnd('remove');

for (let i = 0; i < 100000; i++) {
	map[i] = i;
}

console.time('both same');
for (let i = 0; i < 100000; i++) {
	delete map[0];
	map[0] = 0;
}
console.timeEnd('both same');

console.time('both different');
for (let i = 0; i < 100000; i++) {
	delete map[i % 1000];
	map[i % 1000] = i % 1000;
}
console.timeEnd('both different');

Results on NodeJS:

• Map:

push: 11.795ms
remove: 9.051ms
both same: 7704.086ms
both different: 55.570ms

• Object:

push: 4.001ms
remove: 6.726ms
both same: 7.195ms
both different: 7.479ms