Benchmark: substring vs slice

Script Preparation code:

function sliceRemoveCharAt(str, i) {
  return str.slice(0, i) + str.slice(i+1);
}
function substringRemoveCharAt(str, i) {
  return str.substring(0, i) + str.substring(i+1);
}

Tests:

slice
let str = 'asdfasdfasdfasdfasdfasdf'; sliceRemoveCharAt(str, 2);
substring
let str = 'asdfasdfasdfasdfasdfasdf'; substringRemoveCharAt(str, 2);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
substring

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_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/97.0.4692.71 Safari/537.36

Browser/OS: Chrome 97 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
slice	8788929.0 Ops/sec
substring	9735823.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring JavaScript performance is crucial in web development, and tools like MeasureThat.net help us understand which approaches are faster.

**Benchmark Definition**

The provided JSON represents a benchmark test case that compares the performance of two approaches: `sliceRemoveCharAt` and `substringRemoveCharAt`. These functions are used to remove a character at a specific index from a string.

**Approaches Compared**

1. **Slice**: The `sliceRemoveCharAt` function uses the `slice()` method, which returns a new string containing all characters before and after the specified index.
2. **Substring**: The `substringRemoveCharAt` function uses the `substring()` method, which returns a new string containing all characters before the specified start index.

**Pros and Cons**

*   **Slice Approach**
    *   Pros:
        *   More concise and readable code
        *   No creation of intermediate strings
        *   Typically faster in modern JavaScript engines
    *   Cons:
        *   May require more memory due to creating new strings (although this is often negligible)
*   **Substring Approach**
    *   Pros:
        *   Easier to understand for developers familiar with `substring()` method
        *   Can be beneficial when working with large datasets or performance-critical code
    *   Cons:
        *   May involve more memory allocation and garbage collection due to creating intermediate strings

**Library: Lodash**

The provided benchmark uses the Lodash library, which is a popular JavaScript utility library. The `lodash/each` function is used as part of the test case, but it's not directly related to the performance comparison between `sliceRemoveCharAt` and `substringRemoveCharAt`. However, Lodash can be an additional dependency in your project, and its usage should be considered when comparing the performance of different approaches.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntax used in this benchmark. The code is straightforward and focuses on demonstrating the difference between two string manipulation methods.

**Alternative Approaches**

If you need to remove characters from a string, other approaches include:

*   Using `splice()` method: This approach can be slower than both `slice` and `substring` methods but can provide more control over the resulting string.
    ```javascript
function replaceCharAt(str, i) {
  const arr = str.split('');
  arr.splice(i, 1);
  return arr.join('');
}
```
*   Using regular expressions: This approach can be slower than `slice` and `substring` methods but provides more flexibility in handling complex string patterns.
    ```javascript
function replaceCharAt(str, i) {
  return str.replace(/^.*${i}.*/, '');
}
```

In conclusion, the choice between `sliceRemoveCharAt` and `substringRemoveCharAt` ultimately depends on your specific requirements and preferences. If readability is a top priority, the `slice` approach might be a better fit. However, if you need to work with large datasets or require more control over intermediate strings, the `substring` approach could be more suitable.

Keep in mind that modern JavaScript engines like V8 (used by Chrome) have optimized string manipulation methods, making both approaches relatively fast. The difference in performance might not be significant for small-scale projects but can impact larger applications or those with high-performance requirements.

Related benchmarks:

substring vs slice (version: 0)

Comparing performance of: slice vs substring

Created: 2 years ago by: Guest

Jump to the latest result

slice

substring

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):