var a=[{x:"a", y:"b"},{x:"a1", y:"b"},{x:"a2", y:"b"},{x:"a3", y:"b"},{x:"a4", y:"b"},{x:"a5", y:"b"},{x:"a6", y:"b"}]
var o={a:"b", a1:"b", a2:"b", a3:"b", a4:"b", a5:"b", a6:"b"}
a.map(i=>i.x)
Object.keys(o)
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
map | |
keys |
Test name | Executions per second |
---|---|
map | 739859.6 Ops/sec |
keys | 1495265.9 Ops/sec |
Let's dive into explaining the provided benchmark.
Benchmark Definition and Script Preparation Code
The benchmark is defined in JSON format, which represents two test cases: map
and keys
. The script preparation code is a JavaScript snippet that creates an array a
with 7 objects, each containing x
and y
properties. Another object o
is created, where the keys of o
are the same as the values in a
.
Options being compared
In this benchmark, two options are compared:
a.map(i => i.x)
: This option uses the map()
method to create a new array with the x
property of each object in a
. The map()
method returns a new array and does not modify the original array.Object.keys(o)
: This option uses the keys
method (not the standard Object.keys()
) to get an array of the keys of the object o
.Pros and Cons
a.map(i => i.x)
:Object.keys(o)
:In general, using map()
can be beneficial when you need to process data in parallel or transform it in some way. However, if memory allocation is a concern, using Object.keys()
might be a better choice.
Library and Purpose
There is no explicit library mentioned in the benchmark definition. The keys
method appears to be an internal method used by browsers to get an array of object keys.
Special JS Features or Syntax
None are explicitly mentioned.
Other Alternatives
For creating arrays with transformed data, other options might include:
forEach()
loop instead of map()
: a.forEach(i => o.push(i.x))
...
) to create a new array: o = [...a.map(i => i.x)]
However, these alternatives are not used in this benchmark.
Device Platform and Operating System
The device platform is listed as "Other", which suggests that the test was run on a browser or emulator. The operating system is listed as "Windows 8.1".
Additional Considerations
ExecutionsPerSecond
value indicates how many times each test case was executed per second.I hope this explanation helps!