const g = { e: [] }g.o = function(x) { g.e.push([1,2,3]) }g.o()let g = { e: [] }g.o = function(x) { g.e.push([1,2,3]) }g.o()var g = { e: [] }g.o = function(x) { g.e.push([1,2,3]) }g.o()--enable-precise-memory-info flag.
| Test case name | Result |
|---|---|
| test1 | |
| test2 | |
| test3 |
| Test name | Executions per second |
|---|---|
| test1 | 85408680.0 Ops/sec |
| test2 | 21656138.0 Ops/sec |
| test3 | 21311712.0 Ops/sec |
Overview of the Benchmark
The provided benchmark measures the performance of different JavaScript variable declarations (var, let, and const) in a simple function. The test cases are designed to compare the execution speed of these variables in different contexts.
Variable Declaration Comparison
In the benchmark, three test cases are presented:
let keyword for variable declaration.const keyword for variable declaration.var keyword for variable declaration.Pros and Cons of Each Approach
let are that it is block-scoped, which means its scope is limited to the current block (e.g., function or loop). This can lead to better performance because the variable is not visible outside the block. However, if you need to redeclare a let variable with the same name, JavaScript will throw an error.const are that it also has block-scoping and does not allow redeclaration with the same name. Additionally, const is immutable by default, which can improve performance since you don't need to worry about updating the variable's value. However, if you try to modify a const variable, JavaScript will throw an error.var is that its scope is function-scoped, meaning it is visible outside the current function. This can lead to performance issues because the variable can be accessed and modified from multiple places in your code.Library Used
There doesn't appear to be any library used in this benchmark. However, some libraries may influence the results (e.g., optimization techniques or additional functionality).
Special JS Features/Syntax
None of the test cases use special JavaScript features or syntax like ES6 classes, arrow functions, async/await, or Promises.
Other Alternatives
Some possible alternatives to measure variable declaration performance could include:
var with different scope levels (e.g., function, global)These changes could provide a more accurate representation of real-world use cases and help identify which variable declaration is most efficient in various scenarios.
