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void vs typeof on ===
(version: 0)
Comparing performance of:
typeof vs void 0
Created:
4 years ago
by:
Guest
Jump to the latest result
Script Preparation code:
var value = 2;
Tests:
typeof
typeof value === 'undefined'
void 0
value === void 0
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
typeof
void 0
Fastest:
N/A
Slowest:
N/A
Latest run results:
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Measuring performance differences between various approaches is crucial for optimizing code and identifying potential bottlenecks. Let's break down the provided benchmark, explaining what's being tested, the pros and cons of each approach, and other considerations. **Benchmark Definition** The benchmark is designed to compare two approaches: 1. `typeof` operator 2. Using a literal value `void 0` **Script Preparation Code** ```javascript var value = 2; ``` This sets up a simple variable `value` with the initial value of `2`. **What's being tested?** The benchmark is testing how these two approaches compare when used in conjunction with the equality operator (`===`) to check if `value` is undefined. The test cases are: 1. Using `typeof`: `typeof value === 'undefined'` 2. Using a literal value: `value === void 0` **Options compared** * `typeof`: checks the type of the variable using the `typeof` operator * `void 0`: uses the literal value `void 0`, which is equivalent to `null` in JavaScript **Pros and Cons** * `typeof`: + Pros: more intuitive, readable, and maintainable way to check for undefined values. + Cons: slower performance compared to using a literal value. * Using a literal value (`void 0`): + Pros: faster performance due to the direct equality comparison with `null`. + Cons: less readable and maintainable than using `typeof`. **Other considerations** In modern JavaScript, using `typeof` is generally considered better practice for checking undefined values. However, if you need a high-performance solution, using a literal value like `void 0` might be acceptable. **Library usage** There's no explicit library mentioned in the benchmark definition or test cases. **Special JS feature** The use of the equality operator (`===`) is not special in this context, as it's a standard JavaScript operator. However, the `typeof` operator and the literal value `void 0` are specific to JavaScript. **Benchmark result** The latest benchmark results show that: * Using `typeof` yields better performance with `1770646016.0` executions per second. * Using a literal value (`void 0`) yields slower performance with `1592508928.0` executions per second. This suggests that, in this specific case, using the `typeof` operator is more efficient than using a literal value like `void 0`. However, keep in mind that these results might vary depending on the specific use case and other factors. **Other alternatives** If you're looking for alternative approaches to compare: * You could try using a function like `isUndefined()` from a library like Lodash or other utilities. * Another option is to use `Number.isUndefined()` (introduced in ECMAScript 2015) which returns true if the value is undefined, but it's not as readable as `typeof` and might be slower. * For non- JavaScript environments, you could consider using a library like TypeScript or other static typing systems that provide type checking functionality.
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