Benchmark: splice() vs copyWithin() for adding element at index

Tests:

splice()
for (var k = 0; k < 100; k++) { var arr = new Array(1000); for (var j = 0; j < arr.length; j++) arr[j] = Math.random(); arr.splice(5, 0, 'test'); }
copyWithin()
for (var k = 0; k < 100; k++) { var arr = new Array(1000); for (var j = 0; j < arr.length; j++) arr[j] = Math.random(); arr.length++; arr.copyWithin(6, 5); arr[5] = 'test'; }

Rendered benchmark preparation results:

Previous results

Test case name	Result
splice()
copyWithin()

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Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.81 Safari/537.36

Browser/OS: Chrome 94 on Mac OS X 10.15.7

Test name	Executions per second
splice()	67.0 Ops/sec
copyWithin()	49.2 Ops/sec

splice() vs copyWithin() for adding element at index (version: 0)