Benchmark: Hash vs insert checks

Script Preparation code:

var arr = [];
var hash = {};

for(var i=0; i < 1000; i++){
  arr.push(i.toString());
  hash[i.toString()] = { val : i.toString() }
}

Tests:

includes check on missing value
if (!arr.includes('missing')){ arr.push('missing'); arr.push('another'); }
includes check on existing value
if (!arr.includes('1')){ arr.push('missing'); arr.push('another'); }
hash set an existing value
hash['1'] = {val : '1'};
hash set a missing value
hash['missing'] = {val : 'missing'};
hash check for missing value then set
if (!hash['missing']) { hash['missing'] = {val : 'missing'}; }
hash check for existing value
if (!hash['1']) { hash['1'] = {val : '1'}; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
includes check on missing value
includes check on existing value
hash set an existing value
hash set a missing value
hash check for missing value then set
hash check for existing value

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36 Edg/90.0.818.66

Browser/OS: Chrome 90 on Windows

View result in a separate tab

Test name	Executions per second
includes check on missing value	775814.8 Ops/sec
includes check on existing value	7120866.5 Ops/sec
hash set an existing value	7930927.5 Ops/sec
hash set a missing value	9079996.0 Ops/sec
hash check for missing value then set	10089365.0 Ops/sec
hash check for existing value	8676646.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared options, pros and cons, library usage, special JS features, and alternatives.

**Benchmark Overview**

The benchmark measures the performance of JavaScript arrays (`arr`) with different types of checks: includes check for existing values, includes check for missing values, hash set operations, and hash check operations. The test cases cover various scenarios to evaluate the efficiency of these checks in a real-world scenario.

**Tested Options**

1. **Includes Check**: Checks if a value is present in the array using the `includes()` method.
2. **Hash Set Operations**: Sets values in a hash object (`hash`) without checking for existence first.
3. **Hash Check Operations**: Checks if a key exists in the hash object (`hash`) before setting its value.

**Comparison**

The benchmark compares the performance of these three options:

| Option | Description |
| --- | --- |
| Includes Check (arr.includes()) | Checks if a value is present in the array by iterating over its elements. |
| Hash Set Operation (hash[key] = ...) | Sets a value directly in the hash object without checking for existence first. |
| Hash Check Operation (if (!hash[key]) { ... }) | Checks if a key exists in the hash object before setting its value. |

**Pros and Cons**

1. **Includes Check**:
	* Pros: Easy to implement, simple syntax.
	* Cons: Iterates over all elements of the array, potentially slow for large arrays.
2. **Hash Set Operation**:
	* Pros: Fast, direct access to hash values without checks.
	* Cons: May cause duplicate keys, and checks can be expensive if the hash is very large.
3. **Hash Check Operation**:
	* Pros: Efficiently handles existing key existence checks before setting new values.
	* Cons: Can lead to slower performance due to additional checks.

**Library Usage**

There is no specific library usage in this benchmark. The `includes()` method and the hash object are built-in JavaScript features.

**Special JS Features**

None mentioned explicitly, but note that `includes()` was introduced in ECMAScript 2019 (ES10) as a method for arrays to check if an element exists within them.

**Alternatives**

Other alternatives for includes checks include:

* Using `indexOf()`, which returns the index of the first occurrence of the specified value or -1 if it's not found.
* Using `findIndex()` and then checking if the result is equal to -1, which can be more efficient for large arrays.

Keep in mind that the optimal approach depends on your specific use case, data structure requirements, and performance constraints.

Related benchmarks:

Hash vs insert checks (version: 0)

Comparing performance of: includes check on missing value vs includes check on existing value vs hash set an existing value vs hash set a missing value vs hash check for missing value then set vs hash check for existing value

Created: 3 years ago by: Guest

Jump to the latest result

includes check on missing value

includes check on existing value

hash set an existing value

hash set a missing value

hash check for missing value then set

hash check for existing value

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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