Benchmark: parseInt vs slice + Number

Script Preparation code:

str = "1875 Tokens";

Tests:

String.slice + Number constructor
Number(str.slice(0, -7));
parseInt
parseInt(str);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
String.slice + Number constructor
parseInt

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36

Browser/OS: Chrome 109 on Mac OS X 10.14.6

View result in a separate tab

Test name	Executions per second
String.slice + Number constructor	2564523.0 Ops/sec
parseInt	2189583.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in the provided benchmark.

**Overview**

The benchmark is comparing two approaches to extract numeric values from a string:

1. Using `String.slice()` with a negative offset to remove non-numeric characters and then converting the resulting string to a number using the `Number` constructor.
2. Using the built-in `parseInt()` function to parse the string directly.

**Options Compared**

The benchmark is testing two options:

* Option A: `String.slice(0, -7)` followed by `Number()`. This approach removes the non-numeric characters from the end of the string and then converts the remaining characters to a number.
* Option B: `parseInt(str)`. This approach parses the entire string at once.

**Pros and Cons**

**Option A (`String.slice(0, -7)` followed by `Number()`):**

Pros:

* Can be useful when you need to extract numeric values from a string while preserving the original character set.
* Allows for more control over the extraction process.

Cons:

* Requires two steps: slicing and converting to number.
* May be slower due to the additional step.

**Option B (`parseInt(str)`):**

Pros:

* Faster, as it only requires one operation.
* More concise and readable code.

Cons:

* May not work correctly if the input string contains non-numeric characters that are not immediately followed by a numeric value.
* May throw an error or return `NaN` (Not a Number) if the parsing fails.

**Other Considerations**

When using `parseInt(str)`, it's essential to consider the second argument, which specifies the radix (base) of the number. If omitted, it defaults to 10 (decimal). For example, `parseInt("0x12a")` would interpret "12a" as a hexadecimal number.

**Library and Special JS Features**

In this benchmark, no libraries are used, and there are no special JavaScript features being tested.

**Alternatives**

Other approaches to extract numeric values from a string include:

* Using regular expressions (e.g., `RegExp.test(str)`).
* Utilizing a library like Moment.js for date parsing.
* Implementing a custom solution using a parser or a tokenizer.

Keep in mind that the choice of approach depends on the specific requirements and constraints of your project.

Related benchmarks:

parseInt vs slice + Number (version: 0)

Test parseInt vs slice (to remove non-numeric portion) + Number constructor

Comparing performance of: String.slice + Number constructor vs parseInt

Created: 2 years ago by: Guest

Jump to the latest result

String.slice + Number constructor

parseInt

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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