Run results for: indexOf vs foreEach

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36

Browser: Chrome 62

Operating system: Mac OS X 10.12.6

Device Platform: Other

Date tested: 6 years ago

Test name	Executions per second
map with indexOf	2593035.0 Ops/sec
foreach with map	1681256.0 Ops/sec

Tests:

map with indexOf
const arr = ["foo", "bar", "baz", "foo", "bar", "foo"]; let newArr = []; newArr= arr.map((word)=>{ return arr.indexOf(word) != arr.lastIndexOf(word) ? "" : word; });
foreach with map
const arr = ["foo", "bar", "baz", "foo", "bar", "foo"]; let newArr = []; let newObj = {}; arr.forEach((input, index) => { if (newObj[input]){ newObj[input] += 1; }else{ newObj[input] = 1; } }); newArr = arr.map((word)=>{ return newObj[word] > 1 ? "" : word; });
map doing nothing
const arr = ["foo", "bar", "baz", "foo", "bar", "foo"]; let newArr = []; newArr= arr.map((word)=>{ return word; });