Benchmark: useMemo vs plain length check

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.1/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.1/umd/react-dom.production.min.js"></script>
<div id="root"></div>

Script Preparation code:

function WithUseMemo() {
    const [iata, setIata] = React.useState('test')
    const isValid = React.useMemo(() => {
        return iata.length === 3
    }, [iata])
    const clickMe = () => {};
    return React.createElement('button', {
        disabled: !isValid
    }, 'Click me!');
}

function WithoutUseMemo() {
    const [iata, setIata] = React.useState('test')
    const isValid = iata.length === 3
    const clickMe = () => {};
    return React.createElement('button', {
        disabled: !isValid
    }, 'Click me!');
}

Tests:

With UseMemo
ReactDOM.render(React.createElement(WithUseMemo), document.getElementById('root'))
Without UseMemo
ReactDOM.render(React.createElement(WithoutUseMemo), document.getElementById('root'))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
With UseMemo
Without UseMemo

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_6_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.6 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 16 on iOS 16.6.1

View result in a separate tab

Test name	Executions per second
With UseMemo	574586.2 Ops/sec
Without UseMemo	630678.8 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided JSON represents a JavaScript benchmark test case that compares two approaches: using the `React.useMemo` hook and performing a plain length check.

**What is being tested?**

The test measures the performance difference between these two approaches in rendering a React component with a button element. The component has a state variable `iata` initialized to "test", which is used to validate its length. The `isValid` variable uses either `React.useMemo` or a plain length check, respectively.

**Options being compared**

1. **Using `React.useMemo`:**
	* Pros:
		+ Can cache the result of the memoized function and reuse it instead of recalculating it on every render.
		+ Helps prevent unnecessary re-renders by ensuring that the component only updates when the dependencies change.
	* Cons:
		+ Adds an extra layer of complexity to the code, as it requires setting up a dependency array.
2. **Plain length check:**
	* Pros:
		+ Simple and straightforward implementation, with fewer lines of code.
	* Cons:
		+ Can lead to unnecessary re-renders if the component's state changes frequently.

**Library used**

The `React` library is used for building and rendering the React components. The `ReactDOM.render` method is used to render the components to the DOM.

**Special JavaScript feature or syntax**

The test case uses the `React` library's `useState` hook to manage the component's state, as well as the `useMemo` hook to memoize the `isValid` calculation. This is a standard way of managing state and computed values in React applications.

**Other considerations**

When choosing between these two approaches, consider the trade-off between performance and code complexity. If you expect the component's state to change frequently, using `React.useMemo` might be a better choice to prevent unnecessary re-renders. However, if you prefer a simpler implementation with fewer lines of code, the plain length check approach might be sufficient.

**Alternative approaches**

If you're not sure about these two approaches or want to explore other options:

1. **Using `React.memo`:**
	* Instead of using `useMemo`, you can wrap your component in `React.memo` and provide a comparison function to determine whether the props have changed.
2. **Using a different caching mechanism:**
	* Consider using alternative caching mechanisms, such as Redux or MobX, which might offer better performance characteristics for your specific use case.

Keep in mind that these alternatives will likely introduce additional complexity and dependencies into your codebase, so weigh the benefits against the trade-offs before making a decision.

Related benchmarks:

useMemo vs plain length check (version: 0)

Comparing performance of: With UseMemo vs Without UseMemo

Created: 2 years ago by: Guest

Jump to the latest result

With UseMemo

Without UseMemo

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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