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for vs reduce
(version: 0)
Comparing performance of:
for vs reduce
Created:
6 years ago
by:
Guest
Jump to the latest result
Script Preparation code:
var data = { 'a': true, 'b': false, 'c': true, 'd': false, 'e': true, 'f': false, 'g': true, 'h': false, 'i': true, 'j': false, 'k': true, 'l': false, 'm': true, 'n': false, 'o': true, 'p': false, 'q': true, 'r': false, 's': true, 't': false, 'u': true, 'v': false, 'w': true, 'x': false, 'y': true, 'z': false, };
Tests:
for
const yes = {}; const no = {}; for (const id of Object.keys(data)) { if (data[id]) { yes[id] = data[id]; } else { no[id] = data[id]; } } console.log(yes); console.log(no); console.log(yes.length, no.length);
reduce
const ids = Object.keys(data); const yes = ids.filter(id => data[id]).reduce((prev, cur) => ({ ...prev, [cur]: data[cur] }), {}); const no = ids.filter(id => !data[id]).reduce((prev, cur) => ({ ...prev, [cur]: data[cur] }), {}); console.log(yes); console.log(no); console.log(yes.length, no.length);
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
for
reduce
Fastest:
N/A
Slowest:
N/A
Latest run results:
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down what's being tested in this benchmark. **Benchmark Definition** The benchmark defines two test cases: "for" and "reduce". These are approaches to iterate over an object and extract values based on their existence. **Options Compared** In the "for" approach, a traditional `for` loop is used. The loop iterates over each key in the `data` object using `Object.keys(data)`, and for each key, it checks if its value is true. If so, it assigns that value to an object called `yes`, otherwise it assigns it to another object called `no`. Finally, the lengths of these objects are logged. In contrast, the "reduce" approach uses the `Array.prototype.reduce()` method to iterate over each key in the `data` object. The keys are filtered to only include those with a value of true, and for each of these keys, its corresponding value is assigned to an accumulator (the result of previous reductions). This process creates two objects: one with values where the original data's value was true (`yes`), and another with values where it was false (`no`). The lengths of these objects are then logged. **Pros and Cons** - **For Loop**: - Pros: Easy to understand, no additional libraries required. - Cons: Can be slower due to the loop overhead. - **Reduce Method** - Pros: - Can be faster since it avoids explicit loops. - More concise and expressive code. - Cons: - Requires familiarity with the `reduce()` method, which can be a barrier for some developers. - Performance may vary depending on the JavaScript engine. **Library** In both test cases, no external libraries are used beyond built-in JavaScript methods (`Object.keys()`, `Array.prototype.reduce()`). **Special JS Feature or Syntax** The benchmark utilizes the `Array.prototype.reduce()` method and object properties (e.g., `yes[id]`) to manipulate data. These features are standard in modern JavaScript. **Other Alternatives** For iterating over objects, other approaches could include: - Using `Object.entries()` and iterating manually. - Utilizing libraries like Lodash (`_.forIn()`, `_.filter()`) or Ramda (`R.map()`, `R.filter()`). - Leveraging functions like `forEach()` (available in most modern browsers). Keep in mind that these alternatives might add complexity to the code, which may impact readability and maintainability. The "for" loop approach is simple and easy to understand but slower due to its explicit nature. The "reduce" method provides a more concise way of achieving similar results while being potentially faster. However, it requires understanding the `reduce()` method's behavior, which can be unfamiliar for some developers. These alternatives can be useful depending on the specific requirements or performance needs of your project. In conclusion, the "for" loop and "reduce" methods are two common approaches to iterate over objects in JavaScript. While the "for" loop is straightforward but may be slower, the "reduce" method provides a concise way to achieve similar results while potentially being faster.
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