Benchmark: Which equals operator (== vs ===) is faster (string vs int)?

Tests:

test equality
var n = 0; while(true) { n++; if((n).toString()==(100000).toString()) break; }
test strict equality
var n = 0; while(true) { n++; if((n).toString()===(100000).toString()) break; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
test equality
test strict equality

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
test equality	679.2 Ops/sec
test strict equality	677.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The provided benchmark tests two approaches for comparing values: using the loose equality operator (`==`) and the strict equality operator (`===`). The benchmark focuses on strings versus integers, which is an interesting comparison because JavaScript handles this situation differently than some other languages.

**Options compared:**

1. **Loose Equality Operator (`==`):** This operator checks if both operands are equal after applying certain conversions (e.g., `NaN` is equal to itself). When comparing a string with an integer, JavaScript will attempt to convert the integer to a string before comparison.
2. **Strict Equality Operator (`===`):** This operator checks if both operands have the same value and type.

**Pros and Cons of each approach:**

1. **Loose Equality Operator (`==`):**
	* Pros:
		+ More permissive, allowing for implicit conversions that might be intended by the developer.
		+ Can potentially avoid unnecessary string conversion when comparing large numbers.
	* Cons:
		+ May lead to unexpected behavior due to implicit conversions (e.g., `0 == -0`).
		+ Can result in performance issues if the converted value is larger than expected, leading to slower comparisons.
2. **Strict Equality Operator (`===`):**
	* Pros:
		+ Provides a clear and predictable way of comparing values with their original type.
		+ Avoids implicit conversions, reducing potential for unexpected behavior or performance issues.
	* Cons:
		+ Less permissive, which might lead to more explicit code (e.g., `n.toString() === 100000.toString()`).

**Library usage:**

In the provided benchmark definition, there is no library explicitly mentioned. However, JavaScript's built-in functions and operators are used in both test cases.

**Special JS feature or syntax:**

None of the provided benchmark definitions use any special JavaScript features or syntax that would require additional explanation.

**Other alternatives:**

If you're interested in exploring alternative approaches for comparing values in JavaScript, consider the following:

* Using `===` with explicit type conversions (e.g., `n.toString() === 100000.toString()`).
* Utilizing third-party libraries like Lodash (`_.equals()`) or other comparison utilities.
* Implementing custom comparison functions using JavaScript's `Function.prototype.call()` method or `Function.prototype.apply()`.
* Using TypeScript or other statically typed languages to enforce type safety and eliminate loose equality issues.

In conclusion, the MeasureThat.net benchmark highlights the importance of choosing the right operator for comparing values in JavaScript. While `===` provides a clear and predictable way of comparison, `==` can lead to unexpected behavior due to implicit conversions. By understanding the pros and cons of each approach, developers can make informed decisions about their code's performance and maintainability.

Related benchmarks:

Which equals operator (== vs ===) is faster (string vs int)? (version: 1)

Is there a performance benefit to replacing == with ===? Comparing string against integer.

Comparing performance of: test equality vs test strict equality

Created: 3 years ago by: Registered User

Jump to the latest result

test equality

test strict equality

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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