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if undefined comparison
(version: 0)
Comparing performance of:
case 1 vs case 2 vs case 3
Created:
2 years ago
by:
Guest
Go to the latest result
Tests:
case 1
const obj = { 2: true, 7: true } if (obj[3]) { } obj[3] = true;
case 2
const obj = { 2: true, 7: true } if (typeof obj[3] !== 'undefined') { } obj[3] = true;
case 3
const obj = { 2: true, 7: true } if (obj[3] !== undefined) { } obj[3] = true;
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (3)
Previous results
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Test case name
Result
case 1
case 2
case 3
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
2 years ago
)
User agent:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36
Browser/OS:
Chrome 120 on Mac OS X 10.15.7
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Embed
Embed Benchmark Result
<iframe src="https://measurethat.net/Embed?id=532951" width="100%" height="500px"></iframe>
case 2
1018.3M/s
case 1
1009.8M/s
case 3
18.1M/s
View exact numbers
Test name
Executions per second
✓
case 2
1,018,253,568 Ops/sec
case 1
1,009,767,680 Ops/sec
case 3
18,096,204 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net. **Benchmark Definition JSON** The provided benchmark definition JSON represents a simple test case that compares three different approaches to check if a specific property exists in an object: * `if (obj[3])` * `if (typeof obj[3] !== 'undefined')` * `if (obj[3] !== undefined)` These three options are used to check if the property `3` exists in the object `obj`. The properties of these options are as follows: * **Option 1: `if (obj[3])`** + This option uses bracket notation (`obj[3]`) to access the property. If the property does not exist, it returns `undefined`. + Pros: - Simple and concise + Cons: - May be slower due to the lookup operation * **Option 2: `if (typeof obj[3] !== 'undefined')`** + This option uses the `typeof` operator to check if the property is an object or a primitive value. If it's not, it returns `true`. + Pros: - More accurate than bracket notation alone + Cons: - May be slower due to the additional lookup operation and type checking * **Option 3: `if (obj[3] !== undefined)`** + This option uses a simple comparison operator (`!==`) to check if the property is an object or a primitive value. If it's not, it returns `true`. + Pros: - Similar performance to Option 2 + Cons: - May be less accurate than Option 2 due to type coercion **Library and Special JS Features** None of the test cases use any libraries or special JavaScript features beyond standard ECMAScript syntax. **Benchmark Preparation Code** The benchmark preparation code is empty, which means that no additional setup or initialization is required before running the benchmark. **Latest Benchmark Result** The latest benchmark result shows three different execution counts for each test case: * **Test Case 1: `if (obj[3])`** + Executions per second: 1018253568.0 * **Test Case 2: `if (typeof obj[3] !== 'undefined')`** + Executions per second: 1009767680.0 * **Test Case 3: `if (obj[3] !== undefined)`** + Executions per second: 18096204.0 **Other Alternatives** If you're interested in exploring alternative approaches, here are a few options: * Use the `in` operator instead of bracket notation: `if ('3' in obj)` * Use a custom function to check if a property exists: `function hasProperty(obj, prop) { return Object.prototype.hasOwnProperty.call(obj, prop); }` * Use a library like Lodash or Ramda to provide a more concise and expressive way to check for property existence. Keep in mind that these alternatives may have different performance characteristics or trade-offs in terms of readability and maintainability.
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