var name = "name";
var id = "id";
for (let i = 0; i < 80; ++i) {
let result = id + ": 1, " + name + ": someItem";
}
for (let i = 0; i < 80; ++i) {
let result = "".concat(id, ": 1, ", name, ": someItem");
}
for (let i = 0; i < 80; ++i) {
let result = `${id}: 1, ${name}: someItem`;
}
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
using plus operator | |
using concat function | |
using template literals |
Test name | Executions per second |
---|---|
using plus operator | 125826.4 Ops/sec |
using concat function | 117751.7 Ops/sec |
using template literals | 126036.1 Ops/sec |
Let's dive into the explanation.
Benchmark Purpose and Comparison
The provided benchmark measures the performance of three different methods to concatenate strings in JavaScript:
+
operatorconcat()
function${}
)The goal is to find the best solution for concatenating four strings, which is a common operation in many JavaScript applications.
Pros and Cons of Each Approach
+
operator: This method is simple and widely supported, but it can lead to performance issues due to string concatenation creating new objects each time. It's also slower than other methods.concat()
function: The concat()
function is a built-in method that creates a new object by concatenating multiple strings. While it's slightly faster than using the +
operator, it still involves creating and garbage-collecting objects, which can be slower.Template literals have several advantages:
However, template literals might not be supported in older browsers, which could affect the benchmark results.
Library Usage
None of the test cases use any libraries explicitly. However, the concat()
function is a built-in method that uses JavaScript's string concatenation mechanism under the hood.
Special JS Features or Syntax
The benchmark uses the let
keyword for variable declarations (introduced in ECMAScript 2015), which is not a special feature per se but has become increasingly common in modern JavaScript code. Additionally, the use of arrow functions (=>
) is not relevant to this specific benchmark.
Other Alternatives
If you wanted to explore other alternatives, you could consider:
String.join()
method (introduced in ECMAScript 2009)However, these alternatives are not part of the original benchmark and would likely change the outcome of the performance comparison.