var obj = { a: 1, b: 2, c: 3, d: 4, e: 5 };
obj.check = function(name) { return !!this[name]; };
obj.hasOwnProperty( 'd' );
!! obj['d'];
!! obj.d;
obj.check('d');
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
hasOwnProperty | |
bool with Array | |
bool | |
With methode |
Test name | Executions per second |
---|---|
hasOwnProperty | 208678720.0 Ops/sec |
bool with Array | 517099552.0 Ops/sec |
bool | 517026496.0 Ops/sec |
With methode | 242204192.0 Ops/sec |
Let's dive into the world of JavaScript microbenchmarks!
Benchmark Overview
The provided JSON represents a benchmark test case that compares the performance of four different approaches to check if a property exists in an object: hasOwnProperty
, boolean with array syntax (!! obj['d'];
), boolean without array syntax (!! obj.d;
), and calling a custom method (obj.check('d');
).
Approaches Compared
hasOwnProperty
: This approach checks if the property is present in the object using the hasOwnProperty()
method.!!
) to check if a property exists in an array.!! obj.d;
) to check if a property exists in an object.check
on the object and calls it with the property name as an argument.Pros and Cons of Each Approach
hasOwnProperty
:!! obj['d'];
):!! obj.d;
):obj.check('d');
):Library Usage
None of the benchmark test cases use a specific JavaScript library.
Special JS Features or Syntax
There is no special JS feature or syntax used in these benchmark test cases. The only thing unique about !! obj['d'];
is that it's using a non-standard operator (!!
) which is not supported by all browsers.
Other Alternatives
If you need to optimize object property lookup performance, consider the following alternatives:
in
: Instead of hasOwnProperty
, use the in
operator to check if a property exists in an object: !! obj['d'] === true
.By understanding these alternatives and trade-offs, you can make informed decisions when optimizing object property lookup performance in your JavaScript applications.