Run results for: Remove by splice vs copyWithin

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36

Browser: Chrome 91

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Delete by Splice	1290409.0 Ops/sec
Delete by copyWithin	1292873.0 Ops/sec

Script Preparation code:

var array = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99]

function deleteBySplice (array, element) {
  var index = array.indexOf( element );
  if (index !== -1) {
  	array.splice( index, 1 );
  }
}

function deleteByCopyWithin (array, element) {
  var index = array.indexOf( element );
  if (index !== -1) {
  	array.copyWithin( index, index + 1 );
    --array.length;
  }
}

Tests:

Delete by Splice
deleteBySplice( array, 42 ); deleteBySplice( array, 0 ); deleteBySplice( array, 68 );
Delete by copyWithin
deleteByCopyWithin( array, 42 ); deleteByCopyWithin( array, 0 ); deleteByCopyWithin( array, 68 );

Run results for: Remove by splice vs copyWithin

In-place deletion of an element from an array.

Delete by Splice

Delete by copyWithin