Benchmark: split vs object - MeasureThat.net

Script Preparation code:

var a = {'0_up':1,'0_down':2,'0_left':3,'0_right':4};
var b = {0:{'up':1,'down':2,'left':3,'right':4}};

Tests:

A
for ( var i in a ) { if ( a.split( '_' )[ 0 ] === '0' ) { console.log(a[i]); } }
B
for ( var i in b ) { for ( var j in b[i] ) { console.log(b[i][j]); } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
A
B

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

**What is being tested?**

MeasureThat.net is testing the performance difference between two approaches to access properties of objects in JavaScript: using `split()` on the object's key and then accessing the property, or using the object's bracket notation (`b[0].up`, `b[1].down`, etc.).

**Options compared:**

There are two options being compared:

1. **`a.split('_')[0] === '0'`:** This option uses the `split()` method on the object's key (`_`) and then checks if the resulting array contains only one element, which is expected to be `'0'`. If this condition is true, it logs the value of the property associated with that key.
2. **`b[0].up`, `b[1].down`, etc.:** This option uses the object's bracket notation (`b[i]`) to access the properties.

**Pros and Cons:**

1. **`a.split('_')[0] === '0'`:**
	* Pros:
		+ Can be faster since it avoids the overhead of iterating over an array.
	* Cons:
		+ May not work as expected if the key contains multiple underscores (e.g., `'0_abc'`) or is not exactly equal to `'0'`.
		+ Requires a fixed length prefix on the key, which may limit its flexibility.
2. **`b[0].up`, `b[1].down`, etc.:**
	* Pros:
		+ More flexible and accurate since it directly accesses the property without relying on string manipulation.
		+ Works with any valid object keys, regardless of their structure or values.
	* Cons:
		+ May be slower due to the overhead of iterating over an array (in this case, just one element).
		+ Requires more code to achieve the same result.

**Library and purpose:**

There is no explicit library mentioned in the benchmark definition. However, it appears that `a` and `b` are objects, which is a built-in JavaScript data structure.

**Special JS feature or syntax:**

None are explicitly mentioned. The use of bracket notation (`[0]`) for object property access is a standard JavaScript feature, but it's not particularly notable or noteworthy in this context.

**Other alternatives:**

1. **Using `in` operator with a regular expression:** Instead of using `split()` to check the key prefix, you could use a regular expression with the `in` operator to achieve the same result: `if (i in new RegExp('0_\\w+$')) { console.log(a[i]); }`.
2. **Using `keyOf` function:** If you're targeting modern browsers or environments that support it, you can use the `keyOf()` function to access properties by name, which might be more efficient than bracket notation.

Keep in mind that these alternatives are not directly related to the main comparison between `a.split('_')[0] === '0'` and `b[0].up`, but they demonstrate other ways to approach similar problems.

Related benchmarks:

split vs object (version: 0)

Comparing performance of: A vs B

Created: 8 years ago by: Guest

Jump to the latest result

A

B

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):