var example = '2020-03-19T00:00:00'
var result = example.slice(0,6)
var result = example.substring(0,6)
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
slice | |
substring |
Test name | Executions per second |
---|---|
slice | 9607005.0 Ops/sec |
substring | 10184108.0 Ops/sec |
I'll break down the provided JSON data and explain what's being tested, the different approaches compared, their pros and cons, and other considerations.
Benchmark Definition
The benchmark definition is a simple JavaScript code snippet that defines two functions: slice
and substring
. Both functions are used to extract a subset of characters from a string. The specific implementation details are not provided in the benchmark definition, so we'll have to infer them based on the provided test cases.
Script Preparation Code
The script preparation code is a single line that defines a variable example
with the value '2020-03-19T00:00:00'
. This variable will be used as input for both the slice
and substring
functions.
Individual Test Cases
There are two test cases:
var result = example.slice(0,6)
, which attempts to extract 6 characters from the beginning of the example
string.var result = example.substring(0,6)
, which also attempts to extract 6 characters from the beginning of the example
string.Comparison
The two test cases compare the performance of the slice
and substring
methods for extracting a subset of characters from a string. Both methods are part of the ECMAScript standard and have similar syntax, but they work differently under the hood.
Approach 1: String.prototype.slice()
The slice()
method returns a new string that is a subset of the original string. It uses the following steps:
start
and end
, which define the range of characters to extract.start
index and ending at the end
index (exclusive).Pros:
substring()
because it doesn't create an intermediate string object.Cons:
start
is greater than end
.Approach 2: String.prototype.substring()
The substring()
method returns a new string that is a subset of the original string. It uses the following steps:
start
and end
, which define the range of characters to extract.start
index and ending at the end
index (exclusive).Pros:
start
is greater than end
.Cons:
Library Usage
In the provided benchmark definition, there is no explicit library usage. However, it's worth noting that slice()
and substring()
are built-in methods of the String prototype in JavaScript.
Special JS Feature/Syntax
There are no special JS features or syntax used in this benchmark. The code snippets are straightforward and follow standard ECMAScript syntax.
Other Alternatives
If you need to extract a subset of characters from a string, there are other alternatives:
match()
method: var result = example.match(/2020-03-\d\d/)[0]
.lodash
or underscore
, which provide utility functions for string manipulation.string-slice
.Keep in mind that these alternatives may have different performance characteristics and use cases compared to the built-in slice()
and substring()
methods.