Benchmark: get string but first case

Script Preparation code:

var str = 'foo bar baz';
var noop = Function.prototype;

Tests:

slice(1)
if (str.slice(1) == 'oo bar baz') noop();
substr(1)
if (str.substr(1) == 'oo bar baz') noop();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice(1)
substr(1)

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.71 Safari/537.36

Browser/OS: Chrome 94 on Windows

View result in a separate tab

Test name	Executions per second
slice(1)	5135852.0 Ops/sec
substr(1)	5255964.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its test cases.

**What is being tested?**

The benchmark is testing two JavaScript string slicing methods: `str.slice(1)` and `str.substr(1)`. The idea is to compare the performance of these two methods, which are used to extract a substring from a given string.

**Options compared**

In this case, we have two options:

1. **`slice()` method**: The `slice()` method returns a new string that includes only the characters in the specified range.
2. **`substr()` method**: The `substr()` method returns a new string that includes only the characters in the specified range.

**Pros and Cons of each approach:**

* **`slice()` method**:
	+ Pros: More concise and readable syntax, does not modify the original string.
	+ Cons: May be slower than `substr()`, as it creates a new string object.
* **`substr()` method**:
	+ Pros: Can be faster than `slice()`, especially for large strings, since it only returns a substring without creating a new string object.
	+ Cons: Less readable syntax, and can modify the original string.

**Other considerations**

In general, when working with strings in JavaScript, you should avoid using `substr()` if possible, as it can be slower than other methods like `slice()` or using regular expressions. However, `substr()` can still be useful in certain situations where readability is not a top priority.

**Library usage**

There is no library used in this benchmark. The tests only rely on standard JavaScript functionality.

**Special JS feature/syntax**

There are no special JavaScript features or syntaxes mentioned in this benchmark. The code uses basic JavaScript string manipulation methods and does not include any advanced features like async/await, generators, or classes.

**Alternative approaches**

If you wanted to write a similar benchmark, here's an alternative approach:

* You could use regular expressions instead of slicing strings.
* You could use `substring()` instead of both `slice()` and `substr()`.
* You could test other string manipulation methods, such as concatenation, splitting, or searching.

For example, you could add another test case like this:
```json
{
    "Benchmark Definition": "if (str.indexOf('oo') == 2) noop();",
    "Test Name": "indexOf(2)"
}
```
This would test the performance of `indexOf()` compared to the existing `slice()` and `substr()` tests.

I hope this explanation helps! Let me know if you have any further questions.

Related benchmarks:

get string but first case (version: 0)

Comparing performance of: slice(1) vs substr(1)

Created: 3 years ago by: Guest

Jump to the latest result

slice(1)

substr(1)

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):