Run results for: Spread operator vs Push vs Concat in reduce

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.182 Safari/537.36 Edg/88.0.705.81

Browser: Chrome 88

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
spread operator	28918.9 Ops/sec
Push	52095.9 Ops/sec
Concat	8979.9 Ops/sec

Tests:

spread operator
var params = [ 'AF','AL','DZ','AS','AD','AO','AI','A1','AQ','AG','AR','AM','AW','AU','AT','AZ','BS','BH','BD','BB','BY','BE','BZ','BJ','BM','BT','BO','BQ','BA','BW','BV','BR','IO','BN','BG','BF','BI','KH','CM','CA','IC','CV','KY','CF','TD','CL','CN','CX','CC','CO','KM','CD','CG','CK','CR','CI','HR','CU','CW','CY','CZ','DK','DJ','DM','DO','EC','EG','SV','GQ','ER','EE','ET','FK','FO','FJ','FI','FR','GF','PF','TF','GA','GM','GE','DE','GH','GI','GR','GL','GD','GP','GU','GT','GG','GN','GW','GY','HT','HM','HN','HK','HU','IS','IN','ID','IR','IQ','IE','IM','IL','IT','JM','JP','JE','JO','KZ','KE','KI','KP','KR','XK','KW','KG','LA','LV','LB','LS','LR','LY','LI','LT','LU','MO','MG','MW','MY','MV','ML','MT','MH','MQ','MR','MU','YT','MX','FM','MD','MC','MN','ME','MS','MA','MZ','MM','NA','NR','NP','NL','AN','NC','NZ','NI','NE','NG','NU','NF','MK','MP','NO','OM','O1','PK','PW','PS','PA','PG','PY','PE','PH','PN','PL','PT','PR','QA','RE','RO','RU','RW','BL','SH','KN','LC','MF','PM','VC','WS','SM','ST','A2','SA','SN','RS','SC','SL','SG','SX','SK','SI','SB','SO','ZA','GS','SS','ES','LK','SD','SR','SJ','SZ','SE','CH','SY','TW','TJ','TZ','TH','TL','TG','TK','TO','TT','TN','TR','TM','TC','TV','UG','UA','AE','UK','US','UM','XX','UY','UZ','VU','VA','VE','VN','VG','VI','WF','EH','YE','ZM','ZW' ] var other = params.reduce((acc, countryCode) => { var hasVowel = ['A', 'E', 'I', 'O', 'U'].some((c) => countryCode.indexOf(c) !== -1); if (hasVowel) { return [ ...acc, countryCode] } return acc; }, []);
Push
var params = [ 'AF','AL','DZ','AS','AD','AO','AI','A1','AQ','AG','AR','AM','AW','AU','AT','AZ','BS','BH','BD','BB','BY','BE','BZ','BJ','BM','BT','BO','BQ','BA','BW','BV','BR','IO','BN','BG','BF','BI','KH','CM','CA','IC','CV','KY','CF','TD','CL','CN','CX','CC','CO','KM','CD','CG','CK','CR','CI','HR','CU','CW','CY','CZ','DK','DJ','DM','DO','EC','EG','SV','GQ','ER','EE','ET','FK','FO','FJ','FI','FR','GF','PF','TF','GA','GM','GE','DE','GH','GI','GR','GL','GD','GP','GU','GT','GG','GN','GW','GY','HT','HM','HN','HK','HU','IS','IN','ID','IR','IQ','IE','IM','IL','IT','JM','JP','JE','JO','KZ','KE','KI','KP','KR','XK','KW','KG','LA','LV','LB','LS','LR','LY','LI','LT','LU','MO','MG','MW','MY','MV','ML','MT','MH','MQ','MR','MU','YT','MX','FM','MD','MC','MN','ME','MS','MA','MZ','MM','NA','NR','NP','NL','AN','NC','NZ','NI','NE','NG','NU','NF','MK','MP','NO','OM','O1','PK','PW','PS','PA','PG','PY','PE','PH','PN','PL','PT','PR','QA','RE','RO','RU','RW','BL','SH','KN','LC','MF','PM','VC','WS','SM','ST','A2','SA','SN','RS','SC','SL','SG','SX','SK','SI','SB','SO','ZA','GS','SS','ES','LK','SD','SR','SJ','SZ','SE','CH','SY','TW','TJ','TZ','TH','TL','TG','TK','TO','TT','TN','TR','TM','TC','TV','UG','UA','AE','UK','US','UM','XX','UY','UZ','VU','VA','VE','VN','VG','VI','WF','EH','YE','ZM','ZW' ] var other = params.reduce((acc, countryCode) => { var hasVowel = ['A', 'E', 'I', 'O', 'U'].some((c) => countryCode.indexOf(c) !== -1); if (hasVowel) { acc.push(countryCode); } return acc; }, []);
Concat
var params = [ 'AF','AL','DZ','AS','AD','AO','AI','A1','AQ','AG','AR','AM','AW','AU','AT','AZ','BS','BH','BD','BB','BY','BE','BZ','BJ','BM','BT','BO','BQ','BA','BW','BV','BR','IO','BN','BG','BF','BI','KH','CM','CA','IC','CV','KY','CF','TD','CL','CN','CX','CC','CO','KM','CD','CG','CK','CR','CI','HR','CU','CW','CY','CZ','DK','DJ','DM','DO','EC','EG','SV','GQ','ER','EE','ET','FK','FO','FJ','FI','FR','GF','PF','TF','GA','GM','GE','DE','GH','GI','GR','GL','GD','GP','GU','GT','GG','GN','GW','GY','HT','HM','HN','HK','HU','IS','IN','ID','IR','IQ','IE','IM','IL','IT','JM','JP','JE','JO','KZ','KE','KI','KP','KR','XK','KW','KG','LA','LV','LB','LS','LR','LY','LI','LT','LU','MO','MG','MW','MY','MV','ML','MT','MH','MQ','MR','MU','YT','MX','FM','MD','MC','MN','ME','MS','MA','MZ','MM','NA','NR','NP','NL','AN','NC','NZ','NI','NE','NG','NU','NF','MK','MP','NO','OM','O1','PK','PW','PS','PA','PG','PY','PE','PH','PN','PL','PT','PR','QA','RE','RO','RU','RW','BL','SH','KN','LC','MF','PM','VC','WS','SM','ST','A2','SA','SN','RS','SC','SL','SG','SX','SK','SI','SB','SO','ZA','GS','SS','ES','LK','SD','SR','SJ','SZ','SE','CH','SY','TW','TJ','TZ','TH','TL','TG','TK','TO','TT','TN','TR','TM','TC','TV','UG','UA','AE','UK','US','UM','XX','UY','UZ','VU','VA','VE','VN','VG','VI','WF','EH','YE','ZM','ZW' ] var other = params.reduce((acc, countryCode) => { var hasVowel = ['A', 'E', 'I', 'O', 'U'].some((c) => countryCode.indexOf(c) !== -1); if (hasVowel) { return acc.concat(countryCode); } return acc; }, []);

Run results for: Spread operator vs Push vs Concat in reduce

Compare the new ES6 spread operator with array push

spread operator

Push

Concat