const arr = [];
const obj = {};
for(let i = 0; i < 100000; i++) {
arr.push({ value: i });
obj[`${i}`] = i;
}
const start = new Date().getTime();
let end1;
arr.forEach(e => {
if (e.value === 80000) {
end1 = new Date().getTime();
console.log(end1-start);
}
})
let temp = obj['80000'];
const end2 = new Date().getTime();
console.log(end2-start);