Benchmark: typeof vs casting

Script Preparation code:

var a = 9;

var b = '9';

Tests:

typeof
for(let i =0; i < 1000000; i++) { const c = typeof a === 'string' ? parseInt(a) : a; } for(let i =0; i < 1000000; i++) { const c = typeof b === 'string' ? parseInt(b) : b; }
casting
for(let i =0; i < 1000000; i++) { const c = `${a}`; } for(let i =0; i < 1000000; i++) { const c = `${b}`; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
typeof
casting

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's dive into the world of JavaScript microbenchmarks!

**What is being tested?**

The provided JSON represents two benchmark test cases: "typeof vs casting". The goal of these tests is to compare the performance of two approaches:

1. **typeof**: Using the `typeof` operator to check the type of a variable, and then using a ternary expression to cast it to an integer if necessary.
2. **Casting**: Manually converting a string literal to an integer using the `parseInt()` function or template literals (`${a}`) to concatenate and parse.

**Options being compared**

The two approaches are compared in terms of performance, specifically:

* How many executions per second can each approach achieve?

**Pros and Cons of each approach:**

1. **typeof**:
	* Pros:
		+ Easy to read and write
		+ Less chance of errors due to explicit type checking
	* Cons:
		+ May be slower due to the overhead of `typeof`
2. **Casting**:
	* Pros:
		+ Can be faster for certain use cases (e.g., when `parseInt()` is implemented in native code)
	* Cons:
		+ More prone to errors, as manual type conversions can go wrong
		+ Requires more explicit handling of edge cases

**Library usage**

There doesn't seem to be any explicit library usage in these benchmark test cases. However, some libraries like `parseInt()` rely on the implementation details provided by the browser or JavaScript engine.

**Special JS feature/syntax**

The use of template literals (`${a}`) is a relatively recent feature introduced in ECMAScript 2015 (ES6). It allows for more concise string interpolation and concatenation. This syntax might be a factor to consider when writing optimized code, as it can provide performance benefits.

**Other alternatives**

In addition to `typeof` and casting, other approaches could include:

* **Using native integer type**: If the target platform supports it, using an explicit integer type (e.g., `number`) can eliminate the need for conversions.
* **Regular expressions**: For certain use cases, regular expressions can be used to extract numeric values from strings. However, this approach is typically slower and more error-prone than casting or `typeof`.
* **Custom implementation**: Depending on the specific requirements, implementing a custom function or module to handle type conversions could potentially provide better performance.

Keep in mind that the best approach often depends on the specific use case, target platform, and performance requirements.

Related benchmarks:

typeof vs casting (version: 0)

Comparing performance of: typeof vs casting

Created: 2 years ago by: Guest

Jump to the latest result

typeof

casting

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):