arr0 = [];for(var i=0;i<10000;i++){ arr0.push("var "+i);}var other = arr0.slice()var other = [];Array.prototype.push.apply(other, arr0);var other = [arr0];var other = [];for(var i=0;i<arr0.length;i++){ other.push(arr0[i]);}var other = [];other = other.concat(arr0);--enable-precise-memory-info flag.
| Test case name | Result |
|---|---|
| slice | |
| push-apply | |
| the ...operator | |
| for-push | |
| concat |
| Test name | Executions per second |
|---|---|
| slice | 11879.8 Ops/sec |
| push-apply | 6931.0 Ops/sec |
| the ...operator | 2230.7 Ops/sec |
| for-push | 2406.2 Ops/sec |
| concat | 3903.3 Ops/sec |
What is being tested?
MeasureThat.net is testing the performance of different ways to create a shallow copy of an array in JavaScript. The test cases are designed to measure the execution speed of various methods, including:
slice()push() with apply()...)for loop and push()Options compared
The options being compared are different approaches to creating a shallow copy of an array in JavaScript. Each test case has a unique approach, which is measured for its execution speed.
Pros and Cons of each approach:
slice(): This method creates a new array by copying elements from the original array. Pros: concise and efficient. Cons: may not work as expected if the original array is modified.push() with apply(): This method pushes all elements from the original array onto a new array using the apply() method. Pros: can be used with arrays of any type, including nested arrays. Cons: less concise and may have performance overhead due to the use of apply()....): This method creates a new array by spreading elements from the original array. Pros: concise and efficient. Cons: requires JavaScript 2015 or later for support.for loop and push(): This method pushes all elements from the original array onto a new array using a for loop. Pros: can be used with arrays of any type, including nested arrays. Cons: less concise and may have performance overhead due to the use of a for loop.Library usage
None of the test cases explicitly uses a JavaScript library.
Special JS features or syntax
The spread operator (...) is used in one of the test cases, which requires JavaScript 2015 or later for support. The other test cases do not use any special features or syntax.
Other alternatives
There are additional ways to create a shallow copy of an array in JavaScript, including:
Array.from(): This method creates a new array by copying elements from the original array.forEach() loop: This method pushes all elements from the original array onto a new array using a forEach() loop.These alternatives are not included in the test cases provided.
I hope this explanation helps! Let me know if you have any further questions.
