Benchmark: Storing a temporary variable vs repeated function call

Script Preparation code:


var temp = "test";
function func() {
  return temp;  
}

Tests:

function call
for(var i=0; i<100000; i++) { console.log(func()); }
local variable
var local = func(); for(var i=0; i<100000; i++) { console.log(local); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
function call
local variable

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided JSON represents two microbenchmarks to compare the performance of storing a temporary variable versus repeated function calls.

**Options Being Compared**

1. **Storing a temporary variable**: In this approach, a local variable `temp` is declared and assigned the value `"test"`. The function `func()` returns the value of `temp`.
2. **Repeated function call**: In this approach, the function `func()` is called repeatedly 100,000 times in a loop.

**Pros and Cons**

* **Storing a temporary variable**
	+ Pros: This approach avoids repeated overhead of calling the function `func()`. Since the variable is already declared and initialized, there's no need to re-allocate memory or set up the function call stack.
	+ Cons: This approach still incurs the cost of declaring and initializing the local variable `temp`, which may be allocated on the stack. Additionally, if `temp` were a complex object, storing it might lead to additional overhead due to its size and complexity.
* **Repeated function call**
	+ Pros: This approach avoids the overhead of declaring and initializing a local variable, as the function call stack can be reused for each iteration.
	+ Cons: This approach incurs repeated overhead for calling the function `func()`, which may include costs such as:
		- Pushing the function call onto the call stack
		- Retrieving the return value from the function call

**Library Usage**

In both benchmark cases, a library is not explicitly mentioned. However, it's worth noting that the JavaScript engine used by Chrome 53 likely has some built-in optimizations and caching mechanisms for repeated function calls, which might affect the results.

**Special JS Feature/Syntax**

There are no special JS features or syntaxes mentioned in this benchmark. The code uses standard JavaScript syntax, such as variable declarations, function definitions, loops, and console logging.

**Other Alternatives**

If you wanted to explore other approaches, here are a few possibilities:

* **Assigning to a constant**: Instead of using a local variable `temp`, you could declare it as a constant with the `const` keyword. This might have similar performance characteristics to storing a temporary variable.
* **Using a closure**: You could encapsulate the function call and return value within a closure, passing the result as an argument to another function or using it in a different scope. This approach would require additional setup but could potentially avoid repeated overhead for each function call.
* **Measuring memory allocation**: You could add instrumentation to measure the memory allocation costs associated with each approach. This might provide valuable insights into how the JavaScript engine handles local variables versus repeated function calls.

Keep in mind that the performance characteristics of these alternatives would depend on the specific JavaScript engine, browser, and platform being tested.

Related benchmarks:

Storing a temporary variable vs repeated function call (version: 0)

Testing

Comparing performance of: function call vs local variable

Created: 9 years ago by: Guest

Jump to the latest result

function call

local variable

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):