Run results for: += vs join

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:125.0) Gecko/20100101 Firefox/125.0

Browser: Firefox 125

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
+=	33424.0 Ops/sec
push	37708.1 Ops/sec

Script Preparation code:

let a = ""

​x
 
let a = ""​

Tests:

let a = ""
for (i = 0; i < 1000; i++) {
    a += i
}

 
let a = ""for (i = 0; i < 1000; i++) {    a += i}

let a = ""
for (i = 0; i < 1000; i++) {
    a.concat(i)
}

 
let a = ""for (i = 0; i < 1000; i++) {    a.concat(i)}