Uzun değişken isimlerinin çalışma süresi üzerinde çok düşük de olsa bir etkisi vardır.

window.a = 2;
window.b = 3;
window.c = 4;
window.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa = 2;
window.bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb = 3;
window.ccccccccccccccccccccccccccccccccccccccccccccccccc = 4;
var ts = [];

var t = performance.now();
for(var i = 0; i < 1000000; ++i) {
a = b + c;
}
ts.push(performance.now() - t);

var t = performance.now();
for(var i = 0; i < 1000000; ++i) {
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa = bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb+ ccccccccccccccccccccccccccccccccccccccccccccccccc;
}
ts.push(performance.now() - t);

console.log(ts);


Aşağıdan da görebildiğiniz gibi ismi uzun olan versiyıon her seferinde daha uzun bir sürede çalışıyor.

[4.050000000046566, 4.614999999990687]
[4.254999999946449, 4.59499999997206]
[4.054999999993015, 4.584999999962747]
[4.869999999995343, 5.4500000000116415]
[4.074999999953434, 4.570000000006985]
[4.099999999976717, 4.775000000023283]
[4.205000000016298, 4.649999999965075]
[4.205000000016298, 4.669999999983702]
[4.159999999974389, 4.720000000030268]
[4.149999999965075, 4.684999999997672]