Can u explain this output js code?

Question

var a=-3;
for(d=1;d<5;d+=a){
document.write(d);
a++;
}
the output are 1-1-2-2-114
can you tell me why ?

Answer 1

it prints d
increases a by 1
then increases d by a
d pd na nd
1 1. -2 -1
-1 -1. -1 0
0. 0. 0. -1
-1. -1 1. 0
0. 0. 2. 2
2. 2. 3. 5
end of loop
hope this helps

Answer 2

printed d
new a
new d
sorry bout that

Answer 3

i made a table
so the top is the label
and each row represents one stage in the for loop.

Answer 4

pd na nd?

Answer 5

idont understand

Answer 6

yeah, i go it thanks