Run results for: clearing array via pop() vs shift() vs .length = 0 vs = [] - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (X11; Linux; rv:78.0) Gecko/20100101 Firefox/78.0

Browser: Firefox 78

Operating system: Linux

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
pop	35552670.0 Ops/sec
shift	534303900.0 Ops/sec
length	18770510.0 Ops/sec
reassignment	23114220.0 Ops/sec
.splice(0)	10291500.0 Ops/sec

Website performance monitoring

Script Preparation code:

var array = [];

for(var i = 0; i < 100000; i++){array.push(Math.random());}

Tests:

pop
while (array.length > 0) { array.pop(); }
shift
while (array.length > 0) { array.shift(); }
length
array.length = 0
reassignment
array = []
.splice(0)
array.splice(0);