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+= vs join
(version: 0)
Comparing performance of:
+= vs push
Created:
2 years ago
by:
Guest
Go to the latest result
Script Preparation code:
let a = ""
Tests:
+=
let a = "" for (i = 0; i < 1000; i++) { a += i }
push
let a = "" for (i = 0; i < 1000; i++) { a.concat(i) }
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
+=
push
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
2 years ago
)
User agent:
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:125.0) Gecko/20100101 Firefox/125.0
Browser/OS:
Firefox 125 on Windows
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<iframe src="https://measurethat.net/Embed?id=514242" width="100%" height="500px"></iframe>
push
38K/s
+=
33K/s
View exact numbers
Test name
Executions per second
✓
push
37,708 Ops/sec
+=
33,424 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Measuring JavaScript performance is crucial for developers to optimize their applications and ensure smooth user experiences. The provided JSON represents a benchmark test case on the MeasureThat.net website, where users can create and run JavaScript microbenchmarks. The test case compares two approaches: using the `+=` operator (also known as chained assignment) versus using the `concat()` method with the `push()` method. **What are we testing?** We're measuring the performance difference between these two approaches: 1. `+=`: This is a shorthand for "assign and add." It's used to incrementally build up a string by appending a value to an existing string. 2. `concat() + push()`: This approach involves using the `concat()` method to concatenate strings and then pushing values onto an array. **Options compared:** The two options being tested are: 1. `+=` (Chained Assignment) 2. `concat()` + `push()` (Method Call Approach) **Pros and Cons of each approach:** **`+=` (Chained Assignment)** Pros: * More concise and readable code * Can be faster for small strings or arrays, as it avoids the overhead of method calls * Native JavaScript optimization can optimize this approach Cons: * May lead to performance issues if used with large strings or arrays * Can cause memory fragmentation due to frequent string allocations * Less control over the string building process compared to `concat()` + `push()` **`concat()` + `push()` (Method Call Approach)** Pros: * More explicit and controllable way of string concatenation and array manipulation * Avoids memory fragmentation issues associated with `+=` * Can be more efficient for large strings or arrays, as it allows the browser to optimize the allocation process Cons: * Less concise and less readable code compared to `+=` * May have overhead due to method calls * Requires manual management of the array and string concatenation **Library and special JS feature:** There is no specific library mentioned in this test case. However, some browsers (like Chrome) use a technique called "string pooling" to optimize string manipulation. This involves allocating a pool of strings that can be reused throughout the application. **Special JS feature:** There is a notable difference between these two approaches - the way they handle caching and string allocation. The `+=` operator uses a technique called " incremental string building," which avoids creating temporary strings on each iteration, reducing memory allocation overhead. **Alternatives:** Other alternatives for string concatenation in JavaScript include: * Using a template engine like Handlebars or Mustache * Utilizing a dedicated library like Underscore.js or Lodash for string manipulation and array operations * Leveraging modern JavaScript features like `String.prototype.repeat()` (introduced in ECMAScript 2015) for efficient string repetition Keep in mind that the best approach depends on your specific use case, performance requirements, and coding style preferences.
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