var somestr = "hai!";var result = "";for(i = 0; i < 1000; i++) { result = result.concat(somestr);}for(i = 0; i < 1000; i++) { result = result + somestr;}for(i = 0; i < 1000; i++) { result += somestr;}var a = [];for(i = 0; i < 1000; i++) { a.push(somestr);}result = a.join('');--enable-precise-memory-info flag.
| Test case name | Result |
|---|---|
| concat() | |
| plus_operator | |
| plus_eq_operator | |
| Array.join |
| Test name | Executions per second |
|---|---|
| concat() | 2438.7 Ops/sec |
| plus_operator | 2182.8 Ops/sec |
| plus_eq_operator | 1715.5 Ops/sec |
| Array.join | 8296.2 Ops/sec |
Let's break down the benchmark and explain what's being tested.
Benchmark Description
The benchmark is designed to compare the performance of three different approaches for concatenating strings in JavaScript:
concat()+ operator (also known as string addition)+= operator (also known as string concatenation)The goal is to determine which approach is the fastest.
Options Compared
The benchmark compares the performance of each approach on a specific input: a string literal "hai!". The test case is designed to repeat this operation 1000 times, and the results are recorded in terms of the number of executions per second.
Pros and Cons
Here's a brief summary of the pros and cons of each approach:
concat(): This method is generally considered safe and efficient for concatenating strings. However, it can be slower than other approaches because it creates a new string object on each iteration.+ operator: This method is simple to use but can be slow because it involves creating multiple intermediate string objects during the concatenation process.+= operator: This method is also known as "string interpolation" and is often considered faster than using concat() or the + operator because it avoids creating new strings on each iteration.Library
None of these methods rely on any external libraries, so there's no additional information to provide here.
Special JS Features/Syntax
There are no special JavaScript features or syntax being tested in this benchmark. The focus is solely on comparing the performance of different string concatenation approaches.
Alternatives
If you're interested in exploring alternative string concatenation methods, here are a few options:
join(): This method is similar to concat() but can be more efficient for large strings because it uses an optimized internal implementation.template literals: Introduced in ECMAScript 2015 (ES6), template literals provide a convenient way to concatenate strings using placeholders and expression evaluation.Overall, this benchmark provides a straightforward comparison of three common string concatenation methods in JavaScript, which can be useful for optimizing performance-critical code.
