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Number vs + vs parseFloat V2123123
(version: 1)
Comparing performance of:
Number vs Unary + vs parseFloat
Created:
one year ago
by:
Guest
Go to the latest result
Script Preparation code:
v = Math.random().toString()
Tests:
Number
var number = Number(v);
Unary +
var unary = +v;
parseFloat
var parse = parseFloat(v);
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (3)
Previous results
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Test case name
Result
Number
Unary +
parseFloat
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
one year ago
)
User agent:
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36
Browser/OS:
Chrome 135 on Linux
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Embed Benchmark Result
<iframe src="https://measurethat.net/Embed?id=598014" width="100%" height="500px"></iframe>
Unary +
156.7M/s
Number
146.4M/s
parseFloat
28.7M/s
View exact numbers
Test name
Executions per second
✓
Unary +
156,655,312 Ops/sec
Number
146,434,656 Ops/sec
parseFloat
28,676,308 Ops/sec
Autogenerated LLM Summary
(model
gpt-4o-mini
, generated one year ago):
The benchmark you provided is designed to measure the performance of three different methods for converting a string to a number in JavaScript. The three methods being tested are: 1. **Number()**: This function converts the provided value to a number. - **Pros**: The `Number` function can handle a variety of input types, including strings, booleans, and undefined values, converting them to a number type appropriately. It often returns `NaN` for non-numeric strings, which can be useful in error-checking contexts. - **Cons**: In certain edge cases, `Number` can yield results that are not intuitive (e.g., `Number(" ")` returns `0`). 2. **Unary Plus (`+`)**: This is a unary operator that attempts to convert its operand into a number. - **Pros**: It’s often faster than the `Number` function as it simply coerces the value without being a function call, which can be beneficial in performance-sensitive applications. - **Cons**: Similar to `Number`, the unary plus also returns `NaN` for non-numeric strings. However, its behavior may be slightly less predictable in some cases, especially if the input is not strictly a string. 3. **parseFloat()**: This function parses a string argument and returns a floating-point number. - **Pros**: `parseFloat` can successfully parse numbers within strings and will ignore whitespace at the beginning. It is particularly useful when you are certain that the string value may be a partially valid numeric string. - **Cons**: If the string does not start with a number, `parseFloat` returns `NaN`, and it cannot process more complex numeric formats (e.g., scientific notation), making it less versatile compared to the first two methods. ### Benchmark Results: The benchmark results showed the following executions per second: - **Unary +**: 156,655,312 executions/second (fastest) - **Number()**: 146,434,656 executions/second (second fastest) - **parseFloat()**: 28,676,308 executions/second (slowest) From these results, it is clear that the unary plus operator is the most efficient method for converting strings to numbers in this context. ### Considerations: - If performance is crucial in a specific application, using the unary plus operator is advisable. - If you need more robust error handling or need to deal with different data types, `Number()` is a better choice. - If the input may contain partially valid numeric strings, `parseFloat()` would be needed, but it generally performs worse in terms of speed. ### Alternatives: In addition to the methods tested, other alternatives for converting strings to numbers exist, such as: - **parseInt()**: Similar to `parseFloat()`, but it converts to an integer and can also ignore leading whitespace. It only returns integer values, which can be beneficial when working with whole numbers but is less useful for decimal values. When working with numeric values in JavaScript, one should consider the context and requirements of the application when choosing between these methods to ensure both performance and reliability.
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