Benchmark: pre-increment increment vs post-increment increment vs assignment operator

Script Preparation code:

let i = 0;

Tests:

pre-increment
++i
post-increment
i++
addition assignment operator
i += 1
operation plus (pre number)
i = 1 + i
operation plus (post number)
i = i + 1

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
pre-increment
post-increment
addition assignment operator
operation plus (pre number)
operation plus (post number)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 5 hours ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
pre-increment	16244352.0 Ops/sec
post-increment	16382161.0 Ops/sec
addition assignment operator	16698586.0 Ops/sec
operation plus (pre number)	16636454.0 Ops/sec
operation plus (post number)	16877666.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is testing different ways to increment a variable `i` in JavaScript. The benchmark definition is provided as a JSON object, which specifies:

* Four different operations:
	+ Pre-increment (`++i`)
	+ Post-increment (`i++`)
	+ Addition assignment operator (`i += 1`)
	+ Operation with pre-number calculation (`i = 1 + i`)

**Script Preparation Code**

The script preparation code is `let i = 0;`, which initializes the variable `i` to 0 before running each test.

**Options Compared**

The benchmark is comparing four different approaches:

1. **Pre-increment (`++i`)**: This increments `i` first and then returns its new value.
2. **Post-increment (`i++`)**: This returns the current value of `i`, and then increments it.
3. **Addition assignment operator (`i += 1`)**: This adds 1 to `i` and assigns the result back to `i`.
4. **Operation with pre-number calculation (`i = 1 + i`)**: This calculates the new value of `i` by adding 1 to its current value.

**Pros and Cons**

Here's a brief summary of each approach:

* **Pre-increment (`++i`)**: Generally faster because it can be optimized by the compiler. However, it may not work as expected in certain situations.
* **Post-increment (`i++`)**: Can be slower than pre-increment due to the extra operation of returning the value before incrementing. However, it is often safer and more intuitive.
* **Addition assignment operator (`i += 1`)**: Fast and efficient because it directly modifies `i`. However, it may not be as readable or intuitive for some developers.
* **Operation with pre-number calculation (`i = 1 + i`)**: Can be slower than the other approaches due to the extra calculation. However, it is a more traditional way of incrementing a variable.

**Library and Special JS Features**

None of these approaches require any specific libraries or special JavaScript features beyond basic syntax support.

**Other Alternatives**

Some alternative ways to increment a variable in JavaScript include:

* Using `i++` with parentheses: `(i++)`
* Using a temporary variable: `let temp = i; ++temp;`
* Using a loop: `for (i = 0; ++i < someCondition; )`

However, these alternatives are not typically used for simple incrementing operations like this benchmark.

**Benchmark Results**

The latest benchmark results show the execution speed per second for each test case:

* Post-increment (`++i`): 94676856.0
* Pre-increment (`i++`): 92663480.0
* Addition assignment operator (`i += 1`): 53744980.0
* Operation with pre-number calculation (`i = 1 + i`): 52630928.0

These results suggest that post-increment and addition assignment operators are faster than pre-increment, while the operation with pre-number calculation is slower.

Overall, this benchmark helps compare the performance of different incrementing operations in JavaScript and provides insights into the execution speed and efficiency of each approach.

Related benchmarks:

pre-increment increment vs post-increment increment vs assignment operator (version: 0)

Comparing performance of: pre-increment vs post-increment vs addition assignment operator vs operation plus (pre number) vs operation plus (post number)

Created: 3 years ago by: Guest

Jump to the latest result

pre-increment

post-increment

addition assignment operator

operation plus (pre number)

operation plus (post number)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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