Run results for: Iterator/generator vs. forEach vs. for...of

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_4_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.4 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 16

Operating system: iOS 16.4.1

Device Platform: Mobile

Date tested: one year ago

Test name	Executions per second
Generator populating a map via for...of	3.6 Ops/sec
Generator populating a map via Map.prototype.constructor	2.4 Ops/sec
recursively add to map using Array.prototype.forEach	10.8 Ops/sec
recursively add to map using for...of	11.9 Ops/sec

Script Preparation code:

var nodes = new Array(1000).fill(null).map((_, i) => ({
  id: i,
  nodes: new Array(100).fill(null).map((_, i2) => ({
    id: `${i}-${i2}`,
    nodes: new Array(10).fill(null).map((_, i3) => ({
      id: `${i}-${i2}-${i3}`,
    })),
  })),
}));

Tests:

Generator populating a map via for...of
function* iterateOverNodes(nodes) { for (const node of nodes) { yield [node.id, node]; if (node.nodes) { yield* iterateOverNodes(node.nodes); } } } var map = {}; for (const [id, node] of iterateOverNodes(nodes)) { map[id] = node; }
Generator populating a map via Map.prototype.constructor
function* iterateOverNodes(nodes) { for (const node of nodes) { yield [node.id, node]; if (node.nodes) { yield* iterateOverNodes(node.nodes); } } } var map = new Map(iterateOverNodes(nodes));
recursively add to map using Array.prototype.forEach
function addNodesToMap(nodes, map = {}) { nodes.forEach((n) => { map[n.id] = n; if (n.nodes) { addNodesToMap(n.nodes, map); } }); return map; } addNodesToMap(nodes);
recursively add to map using for...of
function addNodesToMap(nodes, map = {}) { for (const n of nodes) { map[n.id] = n; if (n.nodes) { addNodesToMap(n.nodes, map); } } return map; } addNodesToMap(nodes)

Run results for: Iterator/generator vs. forEach vs. for...of

Recurse through a nested data structure using iterator/generator vs. forEach vs. for...of

Generator populating a map via for...of

Generator populating a map via Map.prototype.constructor

recursively add to map using Array.prototype.forEach

recursively add to map using for...of