Benchmark: Map vs Object 1234

Script Preparation code:

const map = new Map();
const obj = {};

const count = 1000
const l = []

for (let x=0; x<=count; x++) {
  l.push([[''+x, x]])
}

function bMap() {
  'use strict'
  for (let j = 0; i+j < count; j++){
    for (let i = 0; i < count; i++) {
      const [k, v] = l[i]
      const n = map.get(k)
      if (n !== undefined) {
          map.set(k, v)
      } else {
          map.set(k, v+j)
      }
    }
  }
}

function bObj() {
  'use strict'
  for (let j = 0; i+j < count; j++){
    for (let i = 0; i < count; i++) {
      const [k, v] = l[i]
      const n = obj[k]
      if (n !== undefined) {
          obj[k] = v
      } else {
          obj[k] = v+j
      }
    }
  }
}

Tests:

Map lookup
bMap()
Obj lookup
bObj()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map lookup
Obj lookup

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

Let's dive into explaining the provided benchmark.

**Benchmark Purpose**

The primary goal of this benchmark is to compare the performance of two data structures in JavaScript: Maps and Objects, for lookup operations. Specifically, it tests how fast it can iterate over a large dataset (1,000 entries) using both approaches.

**Options Compared**

Two options are being compared:

1. **Map**: A Map data structure, which allows you to store key-value pairs and provides efficient lookup, insertion, and deletion operations.
2. **Object**: An Object data structure, which also allows storing key-value pairs but is more lightweight than Maps. However, it's not designed for fast lookups.

**Pros and Cons of Each Approach**

*   **Map:**
    *   Pros:
        *   Faster lookup times due to its internal hash table implementation.
        *   More flexible and expressive syntax (e.g., `map.set(key, value)`).
    *   Cons:
        *   Higher memory usage compared to Objects.
        *   May incur additional overhead for iterating over the keyspace.
*   **Object:**
    *   Pros:
        *   Smaller memory footprint compared to Maps.
        *   Simpler syntax (e.g., `obj[key] = value`).
    *   Cons:
        *   Slower lookup times due to the Object's linear search algorithm.

**Library and Special JS Features**

Neither of the benchmark's test cases uses any external libraries. However, it does utilize some special JavaScript features:

*   **Strict Mode**: Both `bMap()` and `bObj()` are run in strict mode (`'use strict'`), which enables additional checks for common programming errors.

**Other Considerations**

When choosing between Maps and Objects, consider the following factors:

1.  **Performance:** If you need fast lookups or frequent insertions/deletions, use a Map.
2.  **Memory usage:** For lightweight applications with limited memory resources, use an Object.
3.  **Readability and expressiveness:** Use a Map when you need to emphasize the key-value relationship between data points.

**Alternatives**

In case you're unsure about which approach to use or want to explore other options:

*   **Arrays:** Arrays are another common data structure in JavaScript. While not designed for fast lookups, they offer efficient iteration and indexing capabilities.
*   **Set Data Structures:** Similar to Maps but optimized for fast membership testing (i.e., checking if an element exists).
*   **Dictionaries or Hash Tables:** Some programming languages use these data structures for fast key-value lookups.

In conclusion, the Map vs Object 1234 benchmark provides a useful comparison of performance between two fundamental JavaScript data structures. Understanding the trade-offs between Maps and Objects can help developers choose the right approach for their specific needs.

Related benchmarks:

Map vs Object 1234 (version: 0)

Lookup of map vs object

Comparing performance of: Map lookup vs Obj lookup

Created: 7 years ago by: Guest

Jump to the latest result

Map lookup

Obj lookup

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):