Benchmark: multiple map iterations

Script Preparation code:

var Map1 = new Map([
  [{}, {}],
  [{}, {}],
  [{}, {}],
  [{}, {}],
  [{}, {}],
  [{}, {}],
  [{}, {}]
]);

var Map2 = new Map([
  [1, 0],
  [2, 0],
  [3, 0],
  [4, 0],
  [5, 0],
  [6, 0],
  [7, 0]
]);

var Map3 = new Map([
  ['a', 'String'],
  ['b', 'String'],
  ['c', 'String'],
  ['d', 'String'],
  ['e', 'String'],
  ['f', 'String'],
  ['g', 'String']
]);

var Map4 = new Map([
  [Symbol(), new Set()],
  [Symbol(), new Set()],
  [Symbol(), new Set()],
  [Symbol(), new Set()],
  [Symbol(), new Set()],
  [Symbol(), new Set()],
  [Symbol(), new Set()]
]);

var Target = new Map();

Tests:

shared variables
let tuple, key, value for (tuple of Map1) { key = tuple[0]; value = tuple[1]; Target.set(key, value); } for (tuple of Map2) { key = tuple[0]; value = tuple[1]; Target.set(key, value); } for (tuple of Map3) { key = tuple[0]; value = tuple[1]; Target.set(key, value); } for (tuple of Map4) { key = tuple[0]; value = tuple[1]; Target.set(key, value); }
non-shared variables
for (const tuple of Map1) { const key = tuple[0]; const value = tuple[1]; Target.set(key, value); } for (const tuple of Map2) { const key = tuple[0]; const value = tuple[1]; Target.set(key, value); } for (const tuple of Map3) { const key = tuple[0]; const value = tuple[1]; Target.set(key, value); } for (const tuple of Map4) { const key = tuple[0]; const value = tuple[1]; Target.set(key, value); }
destructured
for (const [key, value] of Map1) { Target.set(key, value); } for (const [key, value] of Map2) { Target.set(key, value); } for (const [key, value] of Map3) { Target.set(key, value); } for (const [key, value] of Map4) { Target.set(key, value); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
shared variables
non-shared variables
destructured

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's dive into explaining the benchmark.

**What is tested?**

The provided JSON represents a set of JavaScript microbenchmarks that test how quickly different approaches can iterate through arrays and objects in JavaScript.

In this specific benchmark, there are four map objects (Map1 to Map4) created with different types of data: pairs, numbers, and symbols. The objective is to iterate through each map object and perform an operation on the values stored in them. Three individual test cases are defined:

1.  **Shared variables**: In this test case, a shared variable `Target` is used across all iterations.
2.  **Non-shared variables**: Similar to the first test case, but instead of using a shared variable, each iteration uses its own separate variable.
3.  **Destructured**: This test case utilizes destructuring assignment (e.g., `[key, value] = tuple`) to extract values from tuples.

**Options compared:**

The benchmark compares three different approaches for iterating through the map objects:

1.  Using a shared variable (`Target`)
2.  Using non-shared variables
3.  Utilizing destructuring assignment

**Pros and Cons of each approach:**

*   **Shared Variables**: This approach is simple to implement, but it may lead to issues with variable scope and shared state. The `Target` variable is accessed and modified across multiple iterations.
    *   Pros:
        *   Simple implementation
    *   Cons:
        *   Shared state can cause unexpected behavior
*   **Non-Shared Variables**: This approach ensures that each iteration has its own separate variables, which reduces the risk of shared state issues. However, it may require more memory and computation to create new variables for each iteration.
    *   Pros:
        *   Reduces shared state risks
        *   Easier debugging due to isolated scope
    *   Cons:
        *   More memory-intensive
        *   May require more computations due to variable creation
*   **Destructured**: This approach leverages destructuring assignment, which allows for a concise and expressive way of iterating through the map objects. It can be more efficient than traditional loop constructs.
    *   Pros:
        *   Concise code
        *   Efficient iteration
    *   Cons:
        *   May not be as intuitive for those unfamiliar with destructuring

**Other considerations:**

1.  **Memory allocation**: The benchmark creates new variables or objects for each iteration, which can impact memory usage. Care should be taken to minimize unnecessary allocations.
2.  **Scalability**: As the number of iterations increases, the performance differences between these approaches may become more pronounced.

**Alternatives:**

For similar benchmarks, you might consider exploring:

1.  Iterating through an array using `for...of` loops or `Array.prototype.forEach()`
2.  Using `Map.prototype.forEach()` to iterate through a Map object
3.  Utilizing `Object.keys()` and `reduce()` for iterating through an Object

If you're interested in testing other JavaScript features, MeasureThat.net provides a wide range of benchmarks covering various aspects of the language.

Related benchmarks:

multiple map iterations (version: 0)

Comparing performance of: shared variables vs non-shared variables vs destructured

Created: 4 years ago by: Guest

Jump to the latest result

shared variables

non-shared variables

destructured

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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