Benchmark: Switch: String vs Object as expr

Script Preparation code:

function Metric1(name) {this.name = name;}

Metric1.TEST1 = new Metric1("TEST1");
Metric1.TEST2 = new Metric1("TEST2");
Metric1.TEST3 = new Metric1("TEST3");

var Metric2 = {
  TEST1: "TEST1",
  TEST2: "TEST2",
  TEST3: "TEST3"
};

Tests:

String
var i = 0; for (var j = 0; j < 100; ++j) { var metric = Metric2.TEST3; switch(metric) { case "TEST1": i += 1; break; case "TEST2": i += 2; break; case "TEST3": i += 3; break; } }
Object
var i = 0; for (var j = 0; j < 100; ++j) { var metric = Metric1.TEST3; switch(metric) { case Metric1.TEST1: i += 1; break; case Metric1.TEST2: i += 2; break; case Metric1.TEST3: i += 3; break; } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
String
Object

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):

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**Benchmark Overview**

The provided benchmark measures the performance difference between using strings and objects as expressions in a switch statement. The benchmark is designed to test the performance of two different approaches: one that uses string literals (strings) and another that uses object references (objects).

**Script Preparation Code**

The script preparation code defines two classes, `Metric1` and `Metric2`, which are used to create instances for the benchmark. `Metric1` has three properties (`TEST1`, `TEST2`, and `TEST3`) that contain string values, while `Metric2` is an object with the same property values.

**Benchmark Definition**

The benchmark definition contains two test cases:

1. **String**: This test case uses a switch statement with string literals as case values.
2. **Object**: This test case uses a switch statement with object references as case values (specifically, the `Metric1` class instances).

**Options Compared**

Two options are compared in this benchmark:

* **Strings** (`"TEST1"`, `"TEST2"`, `"TEST3"`): used as case values in the switch statement.
* **Objects** (`Metric1.TEST1`, `Metric1.TEST2`, `Metric1.TEST3`): used as case values in the switch statement.

**Pros and Cons**

Using strings:

* Pros:
	+ Easier to read and maintain code
	+ Faster lookup times (hash table-based lookups)
* Cons:
	+ Less flexible (can't dynamically create string literals at runtime)

Using objects:

* Pros:
	+ More flexible (can dynamically create object references at runtime)
	+ Can store additional data with each case value
* Cons:
	+ Slower lookup times (requires hash table-based lookups or explicit comparisons)
	+ More verbose code

**Library and Purpose**

No specific libraries are used in this benchmark.

However, it's worth noting that JavaScript's `switch` statement relies on a mechanism called "switch optimization" to improve performance. This optimization involves looking up the case value in an internal array (if using strings) or a lookup table (if using objects). The choice of using strings or objects as case values can impact this optimization.

**Special JS Feature**

None mentioned, but it's worth noting that JavaScript's `switch` statement does not support dynamic case values. This means that the cases must be known at compile-time, and any attempt to use a dynamically created value would result in a syntax error.

**Other Alternatives**

For comparison purposes, other alternatives could include:

* Using regular expressions instead of switch statements
* Using JavaScript's `switch` statement with array or object literals as case values (e.g., `case [value]`)
* Using third-party libraries that provide optimized switch statements for performance-critical code

However, these alternatives are not part of the benchmark and would require additional modifications to compare their performance.

Related benchmarks:

Switch: String vs Object as expr (version: 0)

Comparing performance of: String vs Object

Created: 9 years ago by: Registered User

Jump to the latest result

String

Object

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):