Benchmark: javascript Split vs Substring

Script Preparation code:

var dates = [
	"01-12-2019",
	"11-11-2064",
	"07-03-2032",
	"08-08-2002",
	"08-01-2001",
	"22-12-2018",
	"28-02-2022",
];

Tests:

Split
for(let i=0; i<dates.length; i++) { let date = dates[i].split("-"); let dateString = date[2]+"-"+date[1]+"-"+date[0]; }
Substring
for(let i=0; i<dates.length; i++) { let dateString = dates[i].substr(6,4)+"-"+dates[i].substr(4,2)+"-"+dates[i].substr(0,2); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Split
Substring

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the provided benchmarking setup and explain what's being tested, compared, and the pros and cons of each approach.

**Benchmark Overview**

The benchmark measures the performance difference between two approaches: `split()` and `substr()` when extracting date components from a string.

**Script Preparation Code**

The script preparation code defines an array of dates in the format "dd-mm-yyyy". This is used as input for the benchmarking test cases.

**Individual Test Cases**

There are two test cases:

1. **"Split"`**
```javascript
for(let i=0; i<dates.length; i++) {
  let date = dates[i].split("-"); // split on "-" delimiter
  let dateString = date[2] + "-" + date[1] + "-" + date[0]; // assemble date string
}
```
This test case uses the `split()` method to split the date string into an array of substrings, and then uses indexing (`date[2]`, `date[1]`, and `date[0]`) to extract the individual date components.

2. **"Substring"`**
```javascript
for(let i=0; i<dates.length; i++) {
  let dateString = dates[i].substr(6,4) + "-" + dates[i].substr(4,2) + "-" + dates[i].substr(0,2); // extract date components using substr()
}
```
This test case uses the `substr()` method to extract specific parts of the date string. The syntax is as follows:

* `dates[i].substr(startIndex, length)` extracts a substring starting at `startIndex` with a length of `length`.

**Comparison**

The benchmark compares the performance of the two approaches: `split()` and `substr()`. The test case with the highest execution rate (in this case, "Split") is considered faster.

**Pros and Cons**

* **"Split"`**
	+ Pros:
		- Easy to read and understand.
		- No need to worry about indexing or substring lengths.
	+ Cons:
		- May require more memory allocations and deallocations due to the creation of intermediate arrays.
		- May be slower if the input string is very large, as it involves multiple iterations over the split strings.
* **"Substring"`**
	+ Pros:
		- More efficient in terms of memory usage, as only a single substring is extracted.
		- Can be faster for large input strings, as it avoids the overhead of creating intermediate arrays.
	+ Cons:
		- Requires careful tuning of indexing values to ensure accurate date component extraction.
		- May be harder to read and understand due to the use of substrings.

**Library/Language Features**

There is no explicit library or language feature being used in this benchmark. However, it's worth noting that the `split()` method is a built-in JavaScript method that splits a string into an array of substrings based on a specified delimiter.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntax being tested in this benchmark. The focus is solely on comparing two basic string manipulation approaches: `split()` and `substr()`.

Related benchmarks:

javascript Split vs Substring (version: 0)

Comparing performance of: Split vs Substring

Created: 5 years ago by: Guest

Jump to the latest result

Split

Substring

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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