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

Autogenerated LLM Summary (model llama3.2:3b, generated 24 days 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.

Latest run results:

Run details: (Test run date: 4 months 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

Test name	Executions per second
case 1	54861408.0 Ops/sec
case 2	49989484.0 Ops/sec
case 3	4544219.0 Ops/sec
case 4	53739304.0 Ops/sec
case 5	54966912.0 Ops/sec

Related benchmarks:

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: 4 months ago by: Guest

Jump to the latest result

case 1

case 2

case 3

case 4

case 5

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 24 days ago):