Run results for: JavaScript filter vs reduce more cases ha

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	574493.0 Ops/sec
Using array filter and object assign	422799.7 Ops/sec
Using array filter and object assign SMALLER array first	509160.9 Ops/sec
Using array filter and object assign SMALLER array first, includes instead of in	432962.1 Ops/sec
Using array filter and reduce + spread + includes	480566.1 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;
Using array filter and object assign SMALLER array first, includes instead of in
PRIMARY_SCOPES = ['a', 'd'] availableScopes = {'a': 'A', 'b': 'B', 'c': 'C', 'd': 'D'} const output = {}; PRIMARY_SCOPES.filter((scope) => Object.keys(availableScopes).includes(scope)).forEach((scope) => { Object.assign(output, { [scope]: availableScopes[scope] }); }); return output;
Using array filter and reduce + spread + includes
PRIMARY_SCOPES = ['a', 'd'] availableScopes = {'a': 'A', 'b': 'B', 'c': 'C', 'd': 'D'} const output = PRIMARY_SCOPES.filter((scope) => Object.keys(availableScopes).includes(scope)).reduce( (result, scope) => ({ ...result, [scope]: availableScopes[scope], }), {}, );

Run results for: JavaScript filter vs reduce more cases ha

Using array filter and reduce + spread

Using array filter and object assign

Using array filter and object assign SMALLER array first

Using array filter and object assign SMALLER array first, includes instead of in

Using array filter and reduce + spread + includes