Benchmark: indexOf vs split for finding sub string

Script Preparation code:

var test1 = 'what a test tester testing'
var test2 = 'test tester'
var test3 = 'mytest'

Tests:

indexOf
var result1 = (test1.indexOf('test') == 1); var result2 = (test2.indexOf('test') == 1); var result3 = (test3.indexOf('test') == 1);
split
var result1 = (test1.split('test')[0].length == 1); var result2 = (test2.split('test')[0].length == 1); var result3 = (test3.split('test')[0].length == 1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
indexOf
split

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated one month ago):

LLMs can make mistakes. Check important info.

Let's dive into the details of this benchmark.

**What is being tested?**

This benchmark compares two different approaches to find the occurrence of a substring within a string:

1. Using the `indexOf()` method
2. Using the `split()` method

**Test Case 1: indexOf()**

In the first test case, we're using the `indexOf()` method to check if the substring `'test'` exists in each of three strings (`test1`, `test2`, and `test3`). The test is checking whether the result of `indexOf()` equals 1 (which means the substring starts at index 0).

```javascript
var result1 = (test1.indexOf('test') == 1);
var result2 = (test2.indexOf('test') == 1);
var result3 = (test3.indexOf('test') == 1);
```

**Test Case 2: split()**

In the second test case, we're using the `split()` method to split each of the three strings (`test1`, `test2`, and `test3`) into an array of substrings whenever the delimiter `'test'` is encountered. The test then checks whether the length of the first element in the resulting array equals 1 (which means the substring starts at index 0).

```javascript
var result1 = (test1.split('test')[0].length == 1);
var result2 = (test2.split('test')[0].length == 1);
var result3 = (test3.split('test')[0].length == 1);
```

**Library and JavaScript Features**

In this benchmark, no external libraries are used. The test cases rely solely on built-in JavaScript methods (`indexOf()` and `split()`).

**Pros and Cons of each Approach**

1. **indexOf()**
	* Pros:
		+ Faster for searching substring occurrences
		+ More efficient when dealing with large strings or multiple searches
	* Cons:
		+ Returns `-1` if the substring is not found (not relevant in this test case)
2. **split()**
	* Pros:
		+ Can be used to split a string into an array of substrings
		+ Can be useful when dealing with complex string manipulation or parsing
	* Cons:
		+ Slower than `indexOf()` for searching substring occurrences (as shown in the benchmark)
		+ Creates additional overhead due to the creation of arrays and strings

**Other Alternatives**

There are other ways to search for a substring within a string, such as using regular expressions (`RegExp`) or iterating over the characters of the string. However, these approaches might be slower or more complex than `indexOf()` or `split()`, respectively.

**Benchmark Results**

The latest benchmark results show that:

* Using `indexOf()` method is faster (9621658.0 executions per second) compared to using the `split()` method (6014002.5 executions per second).

These results suggest that when searching for substring occurrences, using the `indexOf()` method might be a better choice than using the `split()` method, especially for large strings or multiple searches.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36 OPR/102.0.0.0

Browser/OS: Opera 102 on Windows

View result in a separate tab

Test name	Executions per second
indexOf	9621658.0 Ops/sec
split	6014002.5 Ops/sec

Related benchmarks:

indexOf vs split for finding sub string (version: 0)

testing speed

Comparing performance of: indexOf vs split

Created: one year ago by: Guest

Jump to the latest result

indexOf

split

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated one month ago):