var arr = [];
if (arr.length) {
console.log(1);
} else {
console.log(0);
}
if (arr.length > 0) {
console.log(1);
} else {
console.log(0);
}
if (arr.length !== 0) {
console.log(1);
} else {
console.log(0);
}
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
array length | |
array length > 0 | |
array.length !== 0 |
Test name | Executions per second |
---|---|
array length | 253065.7 Ops/sec |
array length > 0 | 261164.5 Ops/sec |
array.length !== 0 | 259865.5 Ops/sec |
Let's break down the provided JSON and explain what is being tested, the options compared, their pros and cons, and other considerations.
Benchmark Definition
The benchmark definition represents three different scenarios for testing the execution speed of JavaScript code related to array length checks:
array.length
: This checks if an empty array has a non-zero length.array.length > 0
: This checks if an array has at least one element.array.length !== 0
: This checks if an array has at least one element and is not empty.Script Preparation Code
The script preparation code creates an empty array arr
before each test case:
var arr = [];
This ensures that all three test cases start with the same initial state, making the comparison of their execution speeds more meaningful.
Html Preparation Code
There is no HTML preparation code provided, which means that the benchmarking process does not involve any complex DOM manipulation or rendering.
Library Used: None
None of the test cases use a JavaScript library. This makes it easier to compare the results directly without any potential interference from external dependencies.
Special JS Features/Syntax: None
There are no special JavaScript features or syntax used in these test cases, such as async/await, promises, or experimental features.
Other Alternatives
If you were to rewrite this benchmark using a different approach, some alternatives could be:
Object.keys(arr).length
instead of arr.length
, which would avoid the issue of undefined
arrays having zero length.Pros and Cons
Here's a brief summary of the pros and cons of each approach:
array.length
:array.length > 0
:array.length !== 0
:Benchmark Results
The latest benchmark results show that:
array length > 0
is the fastest, with an average execution time of approximately 129 million executions per second.array.length !== 0
is slower than both of the above options, but still relatively fast, with an average execution time of around 120 million executions per second.Keep in mind that these results may vary depending on your specific use case and JavaScript environment.