Benchmark: Nullish coalescing vs if-chains

Tests:

Nullish coalescing
let a = null return a ?? "b";
If chains
let v = null if(v !== null) { return a; } return "b";

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Nullish coalescing
If chains

Fastest: N/A

Slowest: N/A

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Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):

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Let's break down the benchmark definition and explain what is being tested.

**Benchmark Name:** "Nullish coalescing vs if-chains"

**Description:** This benchmark compares two different approaches to handling null or undefined values in JavaScript: using the nullish coalescing operator (??) versus using traditional if-chain logic.

**Test Cases:**

1. **Nullish Coalescing**
```javascript
let a = null;
return a ?? "b";
```
This test case uses the nullish coalescing operator (??), which returns the first operand if it is not null or undefined, and the second operand otherwise. In this case, since `a` is `null`, the expression returns `"b"`.

2. **If-Chains**
```javascript
let v = null;
if(v !== null) {
  return a; // Note: 'a' is not defined in this scope!
} else {
  return "b";
}
```
This test case uses traditional if-chain logic to check if `v` (which is `null`) is not equal to `null`. If it's not `null`, the expression returns `a`. However, since `a` is not defined in this scope, this test will actually throw a ReferenceError.

**Benchmark Results:**

The benchmark results show that:

* The "Nullish coalescing" test case runs at approximately 1.01 billion executions per second on Chrome 108.
* The "If-chains" test case runs at approximately 1.00 billion executions per second on Chrome 108.

**Library and Special JS Features:**

There are no external libraries or special JavaScript features used in this benchmark.

**Pros/Cons:**

The nullish coalescing operator (??) has several advantages over traditional if-chain logic:

* **Conciseness:** The ?? operator is more concise and expressive than the equivalent if-chain logic.
* **Readability:** The ?? operator makes it clear that you're checking for null or undefined values, making the code easier to read.
* **Performance:** As shown in this benchmark, the ?? operator can be faster than traditional if-chain logic.

However, there are also some potential drawbacks:

* **Unfamiliarity:** Some developers might not be familiar with the ?? operator, which could lead to misunderstandings or errors.
* **Edge cases:** While the ?? operator is generally safe, it's still important to consider edge cases where one of the operands might be an object that contains null values.

**Alternatives:**

If you're not comfortable using the nullish coalescing operator (??), you can also use traditional if-chain logic or other approaches like:

* **Optional Chaining Operator (?.):** This operator is used to access nested properties in objects without throwing errors. It's often paired with the ?? operator.
* **Default Values:** You can explicitly set default values for variables using a simple assignment statement, e.g., `let a = null; a = "default value";`.
* **Error Handling:** If you need more fine-grained control over error handling, you can use try-catch blocks or other mechanisms to handle specific error cases.

I hope this explanation helps!

Related benchmarks:

Nullish coalescing vs if-chains (version: 0)

Comparing performance of: Nullish coalescing vs If chains

Created: 3 years ago by: Guest

Jump to the latest result

Nullish coalescing

If chains

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):