for 1=i<=10 (sum+=1/i )

Question

I really don't get how this code works if someone could please explain it to me, step by step, that would be great. Thanks.
https://code.sololearn.com/clGLW2pLnyhL/?ref=app

Answer 1

The following lines
for( i=1;i<=10;i++)
sum+=1/i;
do the following:
On the first iteration of the loop,
i is 1, so adds up 1 to sum.
Then on the following iterations of the loop it attempt to add a fraction <1
but since i is an integer it adds 0.
so in the end when printing sum, it prints 1.0.

If you change i to be a float you will see sum incremented by 1/2 + 1/3 + etc...

Answer 2

but is it not the point of the double to store numbers with digits beyond decimal point?

Answer 3

yes and it does( it prints 1.0 rather than just 1) but because i is an integer you never add the decimals to sum in the loop, 1/i is always rounded down to zero for i>1.

Answer 4

so, to store a doble every variable in equation has to be a double. Thank you for your answer.