var cnt = 500 * 1024;
var str = []
for(var i=0; i < cnt; i++) {
str.push( String.fromCharCode(Math.random() * 94 + 32) );
}
str = str.join("");
var regex = function(count) {
var rgx = new RegExp("[\\s\\S]{1," + count + "}", "g");
var parts = str.match(rgx);
};
var slice = function(count) {
var parts = [];
for(var i = 0, len = str.length; i < len; i += count) {
parts.push( str.slice(i, i + count) );
}
};
regex(1);
regex(10);
regex(100);
regex(9 * 1024);
slice(1);
slice(10);
slice(100);
slice(9 * 1024);
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
Testing Regex, Length 1 | |
Testing Regex, Length 10 | |
Testing Regex, Length 100 | |
Testing Regex, Length 9 kB | |
Testing Slice, Length 1 | |
Testing Slice, Length 10 | |
Testing Slice, Length 100 | |
Testing Slice, Length 9 kB |
Test name | Executions per second |
---|---|
Testing Regex, Length 1 | 112.6 Ops/sec |
Testing Regex, Length 10 | 628.7 Ops/sec |
Testing Regex, Length 100 | 1774.2 Ops/sec |
Testing Regex, Length 9 kB | 2232.3 Ops/sec |
Testing Slice, Length 1 | 54.5 Ops/sec |
Testing Slice, Length 10 | 465.4 Ops/sec |
Testing Slice, Length 100 | 4541.1 Ops/sec |
Testing Slice, Length 9 kB | 479225.9 Ops/sec |
Measuring performance and optimizing code is a crucial aspect of software development. MeThatNet provides a platform for JavaScript microbenchmarks to help developers understand the performance implications of their code.
Benchmark Definition
The provided JSON represents a benchmark definition, which defines a test scenario for measuring performance. In this case, we have two functions:
regex(count)
: This function creates a regular expression with a specified length (count
) and searches for matches in a randomly generated string.slice(count)
: This function splits the input string into substrings of equal length (count
) using the String.prototype.slice()
method.Options Comparison
We have two main options to compare:
String.prototype.slice()
method to split the input string into substrings. Performance-wise, this method is generally faster since it's implemented in native code.Pros and Cons
Library: RegExp
The RegExp
library is used to create regular expressions. While it's a built-in JavaScript library, it might not be immediately obvious due to its versatility and flexibility.
Special JS feature or syntax
There are no special JavaScript features or syntax in this benchmark definition.
Other Alternatives
If you prefer alternative approaches for splitting strings:
Array.prototype.map()
to create an array of substrings, but it might be slower than the slice approach due to the overhead of iterating over the array.String.prototype.split()
, which can be used for substring splitting. However, this method is generally slower and less flexible than the slice approach.Keep in mind that performance optimization should always be guided by the specific requirements and constraints of your project.