Run results for: JS Variable Performance (const vs let vs var)

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36 Edg/135.0.0.0

Browser: Chrome 135

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

TEST_1: VAR

41.2M/s

TEST_3: CONST

14.4M/s

TEST_2: LET

13.4M/s

View exact numbers

Test name	Executions per second
✓ TEST_1: VAR	41,223,368 Ops/sec
TEST_3: CONST	14,429,788 Ops/sec
TEST_2: LET	13,421,921 Ops/sec

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

/*your preparation JavaScript code goes here
To execute async code during the script preparation, wrap it as function globalMeasureThatScriptPrepareFunction, example:*/
async function globalMeasureThatScriptPrepareFunction() {
    // This function is optional, feel free to remove it.
    // await someThing();
}

Tests:

TEST_1: VAR
var g = { e: [] } g.o = function(x) { g.e.push(...[1,2,3]) } g.o()
TEST_2: LET
let g = { e: [] } g.o = function(x) { g.e.push(...[1,2,3]) } g.o()
TEST_3: CONST
const g = { e: [] } g.o = function(x) { g.e.push(...[1,2,3]) } g.o()