Benchmark: split vs split vs split vs slice+indexOf

Script Preparation code:

var a = "slkfzesqdmkfbaczeiuncamzieurnamziuenramcizurnmcaizunermdzdezedzdjg qmzzpeoriucbyazpoeruycbaozecyrbazdzedksjdf zedazerbcazoyrbcoaizuyebrcoizedzmkqjsd fzedzedzedzedmkj";

Tests:

split1
a.split(" ", 1);
split10
a.split(" ", 1)[0];
split0
a.split(" ")[0];
slice
a.slice(0, a.indexOf(" "));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
split1
split10
split0
slice

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model gemma2:9b, generated one year ago):

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This benchmark compares different ways to extract the first word from a long string in JavaScript.

Here's a breakdown of each method:

* **`a.split(\" \", 1);`** (Test Name: `split1`) : This uses the `split()` method with a space as the delimiter and a limit of 1. It will split the string at the first space and return an array containing only the first word.
    * **Pros:** Simple and straightforward.
    * **Cons:** Can be slightly slower than other methods, especially if there are multiple spaces in the string.

* **`a.split(\" \", 1)[0];`** (Test Name: `split10`) :  Similar to `split1`, but it accesses the first element of the array returned by `split()`.
    * **Pros:** Essentially the same as `split1`, but may be slightly more performant due to accessing the first element directly.
    * **Cons:** Still potentially slower than other methods for strings with multiple spaces.

* **`a.split(\" \")[0];`** (Test Name: `split0`) : This uses `split()` without a limit, resulting in an array of all words separated by spaces. Then it accesses the first element of this array.
    * **Pros:** Works if there are multiple spaces between words.
    * **Cons:**  Potentially slower than methods that split at a specific point.

* **`a.slice(0, a.indexOf(\" \"));`** (Test Name: `slice`) : This uses `indexOf()` to find the position of the first space and then `slice()` to extract the substring from index 0 up to (but not including) that position.
    * **Pros:** Generally considered the most performant method for this specific task. It avoids creating a new array, potentially saving memory and processing time.
    * **Cons:** Requires two function calls, which can be slightly less readable than `split()`.

**Alternatives:**

*  You could use regular expressions to extract the first word. While powerful, they can be slower for simple tasks like this.

**Key Takeaways:** For extracting a single word from a string in JavaScript, using `slice()` with `indexOf()` is often the most efficient approach. The benchmark results confirm this trend.

Related benchmarks:

split vs split vs split vs slice+indexOf (version: 0)

Comparing performance of: split1 vs split10 vs split0 vs slice

Created: 4 years ago by: Guest

Jump to the latest result

split1

split10

split0

slice

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):