Run results for: flatmap vs filtermap

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/93.0.4577.82 Safari/537.36

Browser: Chrome 93

Operating system: Linux

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
flatmap	773396.2 Ops/sec
filter.map	2795218.0 Ops/sec

Script Preparation code:

var test = [
  {
    id: 1,
    name: 1,
  },
  {
    id: 2,
    name: 12,
  },
  {
    id: 3,
    name: 13,
  },
  {
    id: 4,
    name: 14,
  },
  {
    id: 5,
    name: 15,
  },
  {
    id: 6,
    name: 16,
  }
]

AخA
 
var test = [  {    id: 1,    name: 1,  },  {    id: 2,    name: 12,  },  {    id: 3,    name: 13,  },  {    id: 4,    name: 14,  },  {    id: 5,    name: 15,  },  {    id: 6,    name: 16,  }]

Tests:

flatmap

new Map(test.flatMap(c => {
  if (c.id < 3) {
    return []
  }
  return [[c.id, c]]
}))

 
new Map(test.flatMap(c => {  if (c.id < 3) {    return []  }  return [[c.id, c]]}))

filter.map
new Map(test.filter(c => { return c.id >= 3 }).map(el => [el.id, el]))
new Map(test.filter(c => {
return c.id >= 3
}).map(el => [el.id, el]))

Run results for: flatmap vs filtermap

flatmap

filter.map