Benchmark: typeof vs typeof

Script Preparation code:

var test1=10000
var test2="testing"
var test3=true
var test4=undefined

Tests:

typeof
typeof test1 == "number" typeof test2 == "number" typeof test3 == "number" typeof test4 == "number"
typeof 2
typeof(test1) == "number" typeof(test2) == "number" typeof(test3) == "number" typeof(test4) == "number"

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
typeof
typeof 2

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

**Benchmark Overview**

The benchmark measures the performance difference between using `typeof` with a literal value (e.g., `10000`) versus using it with a string (e.g., `"testing"`). The test also compares the performance of using `typeof` in parentheses versus without them.

**Script Preparation Code**

The script preparation code defines four variables:

* `test1`: an integer literal (`10000`)
* `test2`: a string literal (`"testing"`)
* `test3`: a boolean value (`true`)
* `test4`: an undefined variable (not initialized)

These variables are used in the benchmark test cases.

**Individual Test Cases**

There are two test cases:

1. **`typeof`**: This test case uses `typeof` directly on each variable:
```javascript
typeof test1 == "number"
typeof test2 == "number"
typeof test3 == "number"
typeof test4 == "number"
```
This is the original implementation of the `typeof` operator.

2. **`typeof 2`**: This test case uses parentheses around `test1` and calls `typeof` on it:
```javascript
typeof(test1) == "number"
typeof(test2) == "number"
typeof(test3) == "number"
typeof(test4) == "number"
```
This is a modified implementation of the `typeof` operator, where the function call is used instead of a direct comparison.

**Library Usage**

The benchmark uses the JavaScript engine's built-in `typeof` operator. This operator returns a string describing the type of the value being tested (e.g., `"number"`, `"string"`, etc.).

**Special JavaScript Features**

There are no special JavaScript features mentioned in this benchmark. However, it's worth noting that the use of parentheses around `test1` in the second test case relies on the fact that in JavaScript, function calls and direct comparisons have different semantics.

**Pros and Cons**

Here are some pros and cons for each approach:

* **Original `typeof` implementation**:
	+ Pros: Simple, efficient, and well-supported by most browsers.
	+ Cons: May not be optimized for modern JavaScript engines or architectures.
* **Modified `typeof 2` implementation**:
	+ Pros: May provide better performance due to the function call optimization.
	+ Cons: Less intuitive and may require additional overhead.

**Other Considerations**

When interpreting benchmark results, consider factors such as:

* Browser version and architecture
* JavaScript engine optimization
* Cache effects on repeated measurements

Keep in mind that microbenchmarks like this one are typically used for research or educational purposes to understand the behavior of specific JavaScript features or optimizations.

Related benchmarks:

typeof vs typeof (version: 0)

Comparing performance of: typeof vs typeof 2

Created: 4 years ago by: Guest

Jump to the latest result

typeof

typeof 2

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):