Benchmark: switch vs dictionary lookup

Script Preparation code:

var getCursorClass = (state) => {
    switch (state) {
        case 'pending':
            return 'cursor-wait';
        case 'disabled':
            return 'cursor-not-allowed';
        default:
            return 'cursor-pointer';
    }
}

var cursorClassDict = {
    'pending': 'cursor-wait',
    'disabled': 'cursor-not-allowed',
    'default': 'cursor-pointer'
}
var states = ['pending','disabled', 'default'];

Tests:

Switch
const state = states[Math.floor(Math.random()*states.length)]; return getCursorClass(state)
Dict
const state = states[Math.floor(Math.random()*states.length)]; return cursorClassDict[state]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Switch
Dict

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36 Edg/146.0.0.0

Browser/OS: Chrome 146 on Windows

View result in a separate tab

Test name	Executions per second
Switch	104059992.0 Ops/sec
Dict	44367268.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is testing the performance difference between two approaches:

1. **Switch statement**: The `switch` statement is used to execute different blocks of code based on the value of an expression.
2. **Dictionary lookup**: A dictionary (object) is used to store key-value pairs, where the key is a string and the value is another string.

**Script Preparation Code**

The script preparation code defines two functions:

1. `getCursorClass(state)` uses a `switch` statement to return a cursor class based on the input `state`.
2. `cursorClassDict` is an object that maps states to cursor classes, with the same keys as in the `switch` statement.

**Html Preparation Code**

There is no HTML preparation code provided.

**Individual Test Cases**

The benchmark has two test cases:

1. **Switch**: The script uses the `getCursorClass(state)` function with a random state value selected from an array of states.
2. **Dict**: The script uses the `cursorClassDict[state]` expression to retrieve the cursor class for a random state value.

**Library and Purpose**

The `Math.random()` function is used to generate random numbers, which in this case is used to select a random state value.

**Special JS Features or Syntax**

None are mentioned explicitly in the benchmark code. However, it's worth noting that the use of an array of states (`states`) is a modern JavaScript feature (ECMAScript 2015+), although not particularly complex or performance-critical.

**Pros and Cons of Different Approaches**

1. **Switch Statement**:
	* Pros: Can be more readable for simple cases, allows for more explicit control flow.
	* Cons: Can lead to longer execution paths and slower performance compared to dictionary lookups.
2. **Dictionary Lookup**:
	* Pros: Faster lookup times, can lead to better cache locality.
	* Cons: May require more code and planning to set up the dictionary.

**Other Considerations**

The benchmark is focused on the performance difference between these two approaches. Other factors that might influence performance include:

* The size of the state array (`states`)
* The number of iterations or loops in the script
* Any other operations or computations performed before or after the switch statement and dictionary lookup

**Alternative Approaches**

Other alternatives to consider for similar benchmarking scenarios include:

1. **Array.prototype.indexOf()**: This method can be used to find the index of a state value in the `states` array, which might provide comparable performance to the dictionary lookup.
2. **Regular expressions**: If the states are represented as strings with specific patterns, regular expressions could be used to match and retrieve the corresponding cursor class.
3. **Object.keys() and Array.prototype.indexOf() combination**: This approach uses the `Object.keys()` method to get an array of state values and then uses `Array.prototype.indexOf()` to find the index of a random state value.

Keep in mind that these alternatives might not provide identical performance characteristics as the original dictionary lookup or switch statement approaches, but they could offer interesting variations on the benchmarking theme.

Related benchmarks:

switch vs dictionary lookup (version: 0)

Performance comparison between javascript switch and a dictionary lookup for a simple string return

Comparing performance of: Switch vs Dict

Created: 3 years ago by: Guest

Jump to the latest result

Switch

Dict

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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