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

Script Preparation code:

var a = [0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9];
var c;

Tests:

i++
for(i = 0, len = a.length; i < len; i++) { c = a[i]; }
++i
for(i = 0, len = a.length; i < len; ++i) { c = a[i]; }
i += 1
for(i = 0, len = a.length; i < len; i += 1) { c = a[i]; }
i = i + 1
for(i = 0, len = a.length; i < len; i = i + 1) { c = a[i]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.72 Safari/537.36

Browser/OS: Chrome 89 on Windows

View result in a separate tab

Test name	Executions per second
i++	43981.2 Ops/sec
++i	43408.8 Ops/sec
i += 1	42754.9 Ops/sec
i = i + 1	42589.6 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 is being tested.

**Benchmark Overview**

The benchmark measures the performance difference of four different ways to increment a variable `i` in a loop:

1. `i++`
2. `++i`
3. `i += 1`
4. `i = i + 1`

The test case uses an array `a` with 40 elements, and each iteration of the loop assigns the value of `i` to a variable `c`.

**Library Used**

There is no explicit library mentioned in the benchmark definition or individual test cases. However, it's likely that the JavaScript engine being used (e.g., V8) provides some built-in optimization mechanisms for incrementing variables.

**Options Compared**

Here are the different options being compared:

1. `i++`: Postfix increment, where the value of `i` is incremented after it's used.
2. `++i`: PreINCREMENT, where the value of `i` is incremented before it's used.
3. `i += 1`: Addition assignment, where the value of `i` is incremented by 1.
4. `i = i + 1`: Addition and assignment in a single statement.

**Pros and Cons**

Here are some pros and cons of each option:

* `i++`:
	+ Pros: Simple, easy to read, and likely optimized by most JavaScript engines.
	+ Cons: May incur additional overhead due to the postfix increment operation.
* `++i`:
	+ Pros: Can be optimized away in some cases (e.g., when used in a loop).
	+ Cons: More complex than `i++`, may require more parsing and execution overhead.
* `i += 1`:
	+ Pros: Easy to read, can be optimized as an addition operation.
	+ Cons: May incur additional overhead due to the addition operation.
* `i = i + 1`:
	+ Pros: Can be optimized as an addition operation, easy to understand for beginners.
	+ Cons: More complex than increment operators (`i++`, `++i`), may require more parsing and execution overhead.

**Special JS Features**

There is no special JavaScript feature or syntax used in this benchmark. The code uses standard JavaScript syntax and features, such as loops, arrays, and variable assignments.

**Other Alternatives**

If you want to measure the performance of incrementing variables in other languages or contexts, here are some alternatives:

* C++: Use a language likeGCC or Clang to compile a loop that increments a variable using postfix (`x++`) or preincrement (`++x`).
* Python: Use the `timeit` module to measure the execution time of loops that increment variables using postfix (`x += 1`) or addition assignment (`x = x + 1`).
* Java (with JIT compilation): Compile a loop that increments a variable using postfix (`i++`) or preincrement (`++i`), and use the JVM's Just-In-Time compiler to optimize the performance.

These alternatives can help you compare the performance of incrementing variables in different languages or contexts, but keep in mind that the specific optimizations used by each language may affect the results.

Related benchmarks:

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

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

Created: 3 years ago by: Registered User

Jump to the latest result

i++

++i

i += 1

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 2 months ago):