Run results for: Copy array568

Run details:

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Safari/537.36

Browser: Chrome 70

Operating system: Windows 7

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
var child = JSON.parse(JSON.stringify(parent));	82126.1 Ops/sec
var child = []; for (var i = 0; i < parent.length; i++) { child[i] = parent[i].slice(); }	255697.4 Ops/sec
+= 1: var child = []; for (var i = 0; i < parent.length; i += 1) { child[i] = parent[i].slice(); }	263973.4 Ops/sec

Script Preparation code:

var parent = [
  [0],
  [1,4,4,5,8,6,4,4],
  [5,4,3,2,4,7,6,8],
  [1,3,2,4,5,1,8,6],
  [4,5,3,2,8,7,1,6],
  [4,3,1,8,6,7,1,3],
  [4,5,3,4,10,4,5,3],
  [6,3,8,9,2,3,4,7],
  [9,2,3,7,2,1,10,8],
  [2,5,5,3,5,1,10,9]
];
var sparent = [
  "0",
  "14458644",
  "54324768",
  "13245186",
  "45328716",
  "43186713",
  "453410453",
  "63892347",
  "923721108",
  "255351109"
]

Tests:

var child = JSON.parse(JSON.stringify(parent));
var child = JSON.parse(JSON.stringify(parent));
child[i] = parent[i].slice()/// var child = []; for (var i = 0; i < parent.length; i += 1) { child[i] = parent[i].slice(); }
var child = []; for (var i = 0; i < parent.length; i += 1) { child[i] = parent[i].slice(); }
child[i][j] = parent[i][j]/// var child = []; for (var i = 0; i < parent.length; i += 1) { child[i] = []; for (var j = 0; j < parent[i].length; j += 1) { child[i][j] = parent[i][j]; } }
var child = []; for (var i = 0; i < parent.length; i += 1) { child[i] = []; for (var j = 0; j < parent[i].length; j += 1) { child[i][j] = parent[i][j]; } }
var child = JSON.parse(JSON.stringify(sparent));
var child = JSON.parse(JSON.stringify(sparent));
var child = sparent.slice();
var child = sparent.slice();
child[i] = sparent[i]/// var child = []; for (var i = 0; i < parent.length; i += 1) { child[i] = sparent[i]; }
var child = []; for (var i = 0; i < parent.length; i += 1) { child[i] = sparent[i]; }

Run results for: Copy array568

var child = JSON.parse(JSON.stringify(parent));

child[i] = parent[i].slice()/// var child = []; for (var i = 0; i < parent.length; i += 1) { child[i] = parent[i].slice(); }

child[i][j] = parent[i][j]/// var child = []; for (var i = 0; i < parent.length; i += 1) { child[i] = []; for (var j = 0; j < parent[i].length; j += 1) { child[i][j] = parent[i][j]; } }

var child = JSON.parse(JSON.stringify(sparent));

var child = sparent.slice();

child[i] = sparent[i]/// var child = []; for (var i = 0; i < parent.length; i += 1) { child[i] = sparent[i]; }