Benchmark: if undefined comparison with binary

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;
case 4
const obj = { 2: 1, 7: 1 } if (obj[3] !== 1) { } obj[3] = 1;
case 5
const obj = { 2: 1, 7: 1 } if (obj[3]) { } obj[3] = 1;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
case 1
case 2
case 3
case 4
case 5

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36 OPR/109.0.0.0

Browser/OS: Opera 109 on Windows

View result in a separate tab

case 5

55.0M/s

case 1

54.9M/s

case 4

53.7M/s

case 2

50.0M/s

case 3

4.5M/s

View exact numbers

Test name	Executions per second
✓ case 5	54,966,912 Ops/sec
case 1	54,861,408 Ops/sec
case 4	53,739,304 Ops/sec
case 2	49,989,484 Ops/sec
case 3	4,544,219 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data and explain what's being tested.

**Benchmark Overview**

The benchmark is designed to test the performance of JavaScript engines in comparing an undefined property value with a binary value (true or false). The benchmark involves creating an object `obj` with specific properties, then checking if certain properties exist or have a specific value using various comparison operators (`===`, `!==`, `in`, etc.).

**Options Compared**

The benchmark compares four different approaches to check for the existence of an undefined property:

1. **Direct Property Access**: `if (obj[3])`
2. **Type Comparison with `!`**: `if (typeof obj[3] !== 'undefined')`
3. **Existence Check using `in` Operator**: `if (obj[3] in obj)`
4. **Direct Value Comparison with `===`**: `if (obj[3] !== 1)` (note: this one is not actually checking for undefined, but rather comparing the value to a specific literal)

**Pros and Cons of Each Approach**

1. **Direct Property Access**: Pros: Simple and efficient. Cons: May not work as expected if the property is not yet initialized or does not exist.
2. **Type Comparison with `!`**: Pros: More robust than direct property access, as it checks for both existence and value. Cons: May be slower due to type checking.
3. **Existence Check using `in` Operator**: Pros: Can work even if the property is not initialized or does not exist. Cons: May be slower due to the use of a special operator.
4. **Direct Value Comparison with `===`**: Pros: Fast and simple. Cons: Does not actually check for undefined, as it only compares values.

**Library and Special Features**

None of the benchmark cases use any external libraries or special JavaScript features (e.g., ES6 syntax, async/await, etc.).

**Other Considerations**

When interpreting the benchmark results, consider the following:

* The `ExecutionsPerSecond` value indicates the number of iterations completed by each browser engine per second.
* The results may vary depending on factors like JavaScript engine version, platform, and hardware.

**Alternatives**

If you wanted to modify or add new test cases to this benchmark, here are some possible approaches:

1. **Add more property checks**: Test additional properties, such as `obj[4]`, and compare them using different methods.
2. **Use array-like object tests**: Modify the benchmark to use arrays or objects with varying lengths, and check for specific values or non-existence.
3. **Incorporate object literal syntax**: Update the benchmark to use more advanced object literals (e.g., `{ a: 1, b: { c: 2 } }`) and compare properties using different methods.

By modifying or expanding the benchmark cases, you can gain insights into how JavaScript engines handle various property access scenarios.

if undefined comparison with binary (version: 0)

Comparing performance of: `case 1 vs case 2 vs case 3 vs case 4 vs case 5`

Created: 2 years ago by: Guest

Go to the latest result

case 1

case 2

case 3

case 4

case 5

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

if undefined comparison with binary (version: 0)

Comparing performance of: case 1 vs case 2 vs case 3 vs case 4 vs case 5

Created: 2 years ago by: Guest

Go to the latest result

case 1

case 2

case 3

case 4

case 5

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

Related benchmarks

Comparing performance of: `case 1 vs case 2 vs case 3 vs case 4 vs case 5`