Benchmark: replace vs. slice

Script Preparation code:

var strIn = '#hash';
var strOut = '';

Tests:

replace
strOut = strIn.replace('#', '');
slice
strOut = strIn.slice(1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
replace
slice

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.0

Browser/OS: Firefox 140 on Linux

View result in a separate tab

Test name	Executions per second
replace	12986924.0 Ops/sec
slice	38558308.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data and explain what's being tested, compared, and their pros and cons.

**Benchmark Definition**

The benchmark is designed to compare two approaches for removing the first character from a string: using the `replace()` method versus the `slice()` method. The input string is defined in the "Script Preparation Code" section as `"var strIn = '#hash';\r\nvar strOut = '';\r\n\r\n\r\n"`.

**Options Compared**

Two options are compared:

1. **`strOut = strIn.replace('#', '');`**: This approach uses the `replace()` method to replace the first occurrence of the specified character (`#`) with an empty string.
2. **`strOut = strIn.slice(1);`**: This approach uses the `slice()` method to extract a subset of characters from the original string, starting from the second character (index 1).

**Pros and Cons**

**Replace() Method**

Pros:

* Can be more readable and intuitive for some developers.
* May be more efficient in certain cases due to the way it works internally.

Cons:

* Can be slower than the `slice()` method for large strings because of the overhead of searching for the replacement character.
* May not work correctly if there are multiple occurrences of the specified character, only replacing the first one.

**Slice() Method**

Pros:

* Generally faster and more efficient than the `replace()` method for large strings.
* Can handle any number of characters in the original string without issues.

Cons:

* May be less readable and more challenging to understand for some developers due to its functional programming nature.
* Requires careful handling of indices and bounds checking.

**Library**

None is explicitly mentioned in the provided data. However, it's essential to note that the `slice()` method has been a part of the JavaScript language since ECMAScript 5 (ES5), which means older browsers might not support it or have limited functionality.

**Special JS Feature/Syntax**

There are no special features or syntax used in this benchmark that would be unique to modern JavaScript versions or specific browser implementations. The `slice()` method has been around for a long time, and the `replace()` method is widely supported.

**Other Alternatives**

Some alternative approaches to removing the first character from a string could include:

* Using a regular expression with the `exec()` method: `var regex = /#/.exec(strIn); strOut = strIn.substring(regex.index + 1);`
* Using the `substring()` method with negative indices: `strOut = strIn.substring(-1);` (this is not recommended due to potential issues with index handling)
* Using a library like Lodash or a custom implementation using bitwise operations.

Keep in mind that these alternatives might have varying levels of performance, readability, and browser support compared to the original approaches used in this benchmark.

Related benchmarks:

replace vs. slice (version: 0)

Cut first char from string.

Comparing performance of: replace vs slice

Created: 3 years ago by: Guest

Jump to the latest result

replace

slice

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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