Benchmark: i++ vs ++i vs i += 1

Script Preparation code:

var i = 0;

Tests:

++i
++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i; ++i;
i++
i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++; i++;
i += 1
i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1; i += 1;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
++i
i++
i += 1

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/101.0.4951.67 Safari/537.36

Browser/OS: Chrome 101 on Windows

View result in a separate tab

Test name	Executions per second
++i	18567584.0 Ops/sec
i++	15169088.0 Ops/sec
i += 1	14904480.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring the performance of different JavaScript syntax variations is an essential task in understanding how the language's design affects its execution speed.

The provided benchmark definition json and individual test cases are designed to measure the performance difference between three variations of incrementing a variable:

1.  `++i` (pre-increment): This syntax increments the value of `i` before using it.
2.  `i++` (post-increment): This syntax uses the current value of `i` and then increments it after use.
3.  `i += 1`: This syntax adds 1 to the value of `i` directly.

Now, let's analyze these options and their pros/cons:

**Pre-Increment (`++i`) vs Post-Increment (`i++`) vs Direct Addition (`i += 1`)**

*   **Pre-increment (++)**: This approach is generally faster because it involves a single operation: incrementing the variable. However, this syntax also increments `i` before using its value, which can lead to some cases where the previous value of `i` might be used accidentally.

Pros:
    *   Faster
*   **Post-increment (++)**: This approach is also fast because it only involves a single increment operation on `i`. However, this syntax uses the current value of `i`, which can lead to unexpected behavior in some cases.

Cons:
    *   May lead to unexpected behavior if used carelessly
*   **Direct Addition (`i += 1`)**: This approach is slower because it involves a separate operation for incrementing and adding. However, this syntax avoids the potential issues of pre- and post-increment operations by using a single operation.

Pros:
    *   Avoids potential unexpected behavior
*   Cons:
    *   Slower due to additional operations

**Library Considerations**

There is no apparent library used in these benchmark definitions.

**Special JavaScript Features/Syntax**

None are explicitly mentioned, but it's worth noting that the use of `let` or `const` declarations instead of `var` can affect variable scope and behavior. Additionally, some newer JavaScript features like `async/await`, `Promise` objects, or modules might also influence performance in certain scenarios.

**Other Alternatives**

If you wanted to explore different approaches, here are a few examples:

*   **Early Exit**: Implementing an early exit strategy to stop the incrementation process after reaching a predetermined number of increments.
*   **Loop Unrolling**: Using loop unrolling techniques to increase the efficiency of the loop iterations.
*   **SIMD Instructions**: Leveraging SIMD instructions (Single Instruction, Multiple Data) to execute multiple operations simultaneously.

These alternatives would require significant modifications to the benchmark definitions and test cases.

Related benchmarks:

i++ vs ++i vs i += 1 (version: 0)

Comparing performance of: ++i vs i++ vs i += 1

Created: 2 years ago by: Guest

Jump to the latest result

++i

i++

i += 1

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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