Run results for: Javascript string.endsWith vs string.slice and triple equal checking vs hardcoded index and triple equal, comparing a single character

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_4_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.4 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 18

Operating system: iOS 18.4.1

Device Platform: Mobile

Date tested: one year ago

hardcoded index

456.9M/s

slice

453.1M/s

endWith

73.7M/s

View exact numbers

Test name	Executions per second
✓ hardcoded index	456,867,200 Ops/sec
slice	453,073,856 Ops/sec
endWith	73,705,416 Ops/sec

Script Preparation code:

const value = "ABCDEF...WXYZ"
const ending = "Z"

function compareEndsWith(val, comparator) {
  return val.endsWith(comparator)
}
function compareSliceMethod(val, comparator) {
  const thingToCompare = val.slice(-1)
  return thingToCompare === comparator
}
function compareByIndex(val, comparator) {
	return value[12] === comparator
}

Tests:

endWith
const value = "ABCDEF...WXYZ" const ending = "Z" compareEndsWith(value, ending)
slice
const value = "ABCDEF...WXYZ" const ending = "Z" compareSliceMethod(value, ending)
hardcoded index
const value = "ABCDEF...WXYZ" const ending = "Z" compareByIndex(value, ending)