Run results for: Filtering out empty rows from a 2D Array

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser: Chrome 131

Operating system: Windows

Device Platform: Desktop

Date tested: 11 days ago

Test name	Executions per second
Double negation (!!row.length)	153157.4 Ops/sec
Comparison (row.length > 0)	150694.2 Ops/sec
Double negation (!!row)	115213.0 Ops/sec
Boolean constructor	124618.1 Ops/sec

Script Preparation code:

// Array with alternating empty and non-empty arrays
const arraySize = 1000;
var testArray = new Array(arraySize)
    .fill(null)
    .map((_, i) => i % 2 === 0
        // Make the values alternate between 0-2
        ? new Array(i).fill(0).map((_, j) => j % 2) 
        : []);

function doubleNegateLength({ length }) {
 return !!length; 
}

function lengthGreaterThanZero({ length }) {
  return length > 0;
}

function doubleNegate(value) {
  return !!value;
}

var booleanConstructor = Boolean;

Tests:

Double negation (!!row.length)
testArray.filter(doubleNegateLength);
Comparison (row.length > 0)
testArray.filter(lengthGreaterThanZero);
Double negation (!!row)
testArray.filter(doubleNegate);
Boolean constructor
testArray.filter(booleanConstructor);

Run results for: Filtering out empty rows from a 2D Array

Double negation (!!row.length)

Comparison (row.length > 0)

Double negation (!!row)

Boolean constructor