Benchmark: Concatenation vs substring

Script Preparation code:

var string = "HelloWorld!".repeat(100) + " Hi";

Tests:

Concat
for (let i = 0; i < 200; ++i) { let result = ''; for (let j = 0; j < string.length; ++j) { if (' ' === string[j]) { break; } result += string[j]; } }
Find & Substring
for (let i = 0; i < 200; ++i) { let j; for (j = 0; j < string.length; ++j) { if (' ' === string[j]) { break; } } let result = string.substring(0, j); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Concat
Find & 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 benchmark definition and test cases to understand what is being tested.

**What is being tested?**

The website MeasureThat.net provides a platform for users to create and run JavaScript microbenchmarks. The provided benchmark tests two approaches to concatenate strings: using the `+` operator (`Concat`) and using the `substring()` method (`Find & Substring`).

**Options compared:**

Two options are compared:

1. **Concat**: Using the `+` operator to concatenate strings.
2. **Find & Substring**: Using the `substring()` method to find a substring within a string.

**Pros and Cons of each approach:**

**Concat (using `+` operator):**

Pros:

* Simple and straightforward implementation.
* Likely to be optimized by JavaScript engines, as it's a common operation.

Cons:

* May lead to slower performance due to the creation of temporary strings during concatenation.
* Can result in more memory usage, especially for large strings.

**Find & Substring (using `substring()` method):**

Pros:

* More efficient than using the `+` operator, as it avoids creating temporary strings.
* Can be faster, especially when dealing with large strings or substring searches.

Cons:

* May require additional overhead due to function calls and parameter handling.
* Less intuitive for beginners, as it requires understanding of string manipulation methods.

**Library usage:**

None of the test cases use any external libraries.

**Special JavaScript features or syntax:**

There are no special JavaScript features or syntax mentioned in the benchmark definition. The focus is on comparing two simple string concatenation approaches.

**Alternative approaches:**

Other alternative approaches to string concatenation and substring extraction might include:

* Using `concat()` method (if supported by the browser): This method can provide a balance between performance and readability.
* Using regular expressions (if applicable): Regular expressions can be used to extract substrings, but may require additional overhead due to pattern matching.
* Using array or buffer methods: Depending on the use case, using arrays or buffers to store and manipulate strings might offer performance benefits.

In summary, the benchmark tests two common approaches to concatenating strings in JavaScript: using the `+` operator (`Concat`) and using the `substring()` method (`Find & Substring`). The test results can provide insight into which approach is more efficient for specific use cases.

Related benchmarks:

Concatenation vs substring (version: 0)

Comparing performance of: Concat vs Find & Substring

Created: 5 years ago by: Guest

Jump to the latest result

Concat

Find & 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):