Run results for: JavaScript filter vs reduce more cases

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.60 Safari/537.36

Browser: Chrome 100

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Using array filter and reduce + spread	582422.5 Ops/sec
Using array filter and object assign	432107.6 Ops/sec
Using array filter and object assign SMALLER array first	523630.8 Ops/sec

Tests:

Using array filter and reduce + spread
PRIMARY_SCOPES = ['a', 'd'] availableScopes = {'a': 'A', 'b': 'B', 'c': 'C', 'd': 'D'} const output = PRIMARY_SCOPES.filter((scope) => scope in availableScopes).reduce( (result, scope) => ({ ...result, [scope]: availableScopes[scope], }), {}, );
Using array filter and object assign
PRIMARY_SCOPES = ['a', 'd'] availableScopes = {'a': 'A', 'b': 'B', 'c': 'C', 'd': 'D'} const output = {}; Object.entries(availableScopes).forEach(([key, value]) => { if (!PRIMARY_SCOPES.includes(key)) { return; } Object.assign(output, { [key]: value }); }); return output;
Using array filter and object assign SMALLER array first
PRIMARY_SCOPES = ['a', 'd'] availableScopes = {'a': 'A', 'b': 'B', 'c': 'C', 'd': 'D'} const output = {}; PRIMARY_SCOPES.filter((scope) => scope in availableScopes).forEach((scope) => { Object.assign(output, { [scope]: availableScopes[scope] }); }); return output;