What will the following code output?

Question

const arr = [10, 12, 15, 21];
for (var i = 0; i < arr.length; i++)
{
setTimeout(function() {
console.log('Index: ' + i + ', element: ' + arr[i]);
}, 3000);
}

Answer 1

ans:-

index: 0 , element: 10 // 3sec delay
index: 1 , element: 12// 3sec delay
index: 2 , element: 15// 3sec delay
index: 3 , element: 21 // 3sec delay

Answer 2

Thanks Rajeeb for it interest.

but I am getting this output:-

Index: 4, element: undefined