Need clarification on how the output of this code is 704. Many thanks!

Question

var input = 407;
var res = 0;

for (i = input; i > 0; i = Math.floor(i/10)) {
res = res * 10 + i % 10;
}

document.write(res)

Answer 1

Let's iterate through the loop
iteration 1:
i = 407
res = 0*10 + 7
i = 40
iteration 2:
i = 40
res = 7*10 + 0
i = 4
iteration 3:
i = 4
res = 70*10 + 4
i = 0
out of the loop
res = 704