Vigezo bya msingi katika kutenganua safu ndani ya JavaScript

Kwa vigezu inawezekana kubainisha vigezo bya msingi. Katika hali hii, ikiwa kigezo hakitoshelewi na kipengele cha safu - thamani ya msingi itachukuliwa. Katika mfano ufuatao kigezo day kwa msingi kimebainishwa thamani 1:

javascriptlet arr = [2025, 12];
let [year, month, day = 1] = arr;

console.log(year);  // inatoa 2025
console.log(month); // inatoa 12
console.log(day);   // inatoa 1

Lakini ikiwa kwa kigezo day kutakuwa na thamani ndani ya safu - thamani ya msingi itaachwa:

javascriptlet arr = [2025, 12, 31];
let [year, month, day = 1] = arr;

console.log(year);  // inatoa 2025
console.log(month); // inatoa 12
console.log(day);   // inatoa 31

javascriptlet arr = ['John', 'Smit', 'development', 'programmer'];

let name       = arr[0];
let surname    = arr[1];
let department = arr[2];

let position;
if (arr[3] !== undefined) {
  position = arr[3];
} else {
  position = 'trainee';
}