Run results for: reduce + map filter

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.80 Safari/537.36

Browser: Chrome 75

Operating system: Mac OS X 10.14.6

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
reduce	3455738.0 Ops/sec
map	164271.3 Ops/sec

Script Preparation code:

var customers = [
      { active: true, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: true, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" },
      { active: false, name: "a", email: "b" }
  ];
  
  Array.prototype.filterMap = function(filter) {
     const r = [];
     const len = this.length;
     for(let i=0; i<len; i++) {
        const item = filter(this[i], i, this);
        if (item !== undefined) {
           r.push(item);
        }
     }
     return r;
  };

Tests:

reduce
var emails = customers.filter( (c) => c.active) .map( (c) => ({ name: c.name, email: c.email }));
map
var emails = customers.filterMap( (c) => c.active ? { name: c.name, email: c.email } : undefined);