Benchmark: Which equals operator (== vs ===) is faster? check for null

Tests:

test equality
var n = 0; while(true) { n += (n != null ? 1 : 0) if(n===100000) break; }
test strict equality
var n = 0; while(true) { n += (n !== null && n !== undefined ? 1 : 0) if(n===100000) 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; rv:134.0) Gecko/20100101 Firefox/134.0

Browser/OS: Firefox 134 on Mac OS X 10.15

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Test name	Executions per second
test equality	15251.4 Ops/sec
test strict equality	14567.5 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, compared, and the pros/cons of different approaches.

**Benchmark Test Case Overview**

The benchmark tests two ways to check for nullity in a variable: using the loose equality operator (`==`) versus the strict equality operator (`===`). Both tests are loops that increment a counter until it reaches 100,000. The difference lies in whether the `null` value is treated as equal or not.

**Options Compared**

The benchmark compares two options:

1. **Loose Equality Operator (`==`)**: This operator checks for equality between two values using their string representations (using `toString()` method). It also performs a type check, where if one of the operands is null, it's considered equal to the other operand.
2. **Strict Equality Operator (`===`)**: This operator checks for both value and type equality between two values. If either operand is null, it returns false.

**Pros/Cons**

* **Loose Equality Operator (`==`)**:
	+ Pros: Fastest and most straightforward way to check if a variable is not null.
	+ Cons: Can lead to unexpected results if the `null` value is used in comparison, potentially causing errors or incorrect outcomes.
* **Strict Equality Operator (`===`)**:
	+ Pros: Provides more accurate results by checking both value and type equality. This helps prevent common errors like comparing a numeric value with `null`.
	+ Cons: Generally slower than loose equality due to the additional check.

**Library and Special JS Features**

None of the test cases use any libraries, but they do utilize special JavaScript features:

* **Short-circuit evaluation**: In both tests, the conditional statement (`if`) uses short-circuit evaluation, which means that if the condition is false, the expression after it (in this case, `break`) is not evaluated.
* **Null coalescing operator**: Although not explicitly used in the provided test cases, the null coalescing operator (`??`) can be inferred as part of the logic. The `null` value is treated as equal to zero (`0`) when performing arithmetic operations.

**Alternative Approaches**

Other approaches to check for nullity include:

* **Using `!=` or `!==` instead**: This would change the comparison operators used in both tests.
* **Using a separate function to check nullity**: You could create a custom function that checks if an object is null, which might be more readable and maintainable than using the equality operators directly.

**Benchmark Result Explanation**

The benchmark result shows two execution rates:

1. **Loose Equality Operator (`==`)**: With an execution rate of 19545.0390625 executions per second.
2. **Strict Equality Operator (`===`)**: With an execution rate of 90.98786926269531 executions per second.

These results indicate that the loose equality operator is significantly faster than the strict equality operator, which aligns with our expectations based on their performance characteristics.

Related benchmarks:

Which equals operator (== vs ===) is faster? check for null (version: 0)

Is there a performance benefit to replacing == with ===?

Comparing performance of: test equality vs test strict equality

Created: 4 years ago by: Guest

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):