int sum = 0

Question

in most of the codes i see sum is always equal to zero
so why is that so

Answer 1

It is often set to zero initially, because it serves as a variable slowly adding the rest of the numerical values.

E.g. If you want the sum of 1,2,3,4,5 it would be: sum = 1+2+3+4+5. If you use any other initial value for sum, let's say 1, the sum would be calculated as 1+1+2+3+4+5

Answer 2

Just a quick quiz to see if you really understand now:

Suppose now we are running loops to calculate the product of an array of numbers,

What value should we initialize the variable for storing temp products as?

Answer 3

There is a good reason behind initializing sum to 0.
So basically what is expected from a variable named in this manner might be to store the sum of a collection of data.

So just assume you have a list with values - [1,2,3,4,5] and you want to get the sum. A classic way is iterating through all of the elements and add each number to the variable sum.

So in runtime sum would undergo to changes like this

sum = (((((1) + 2) + 3) + 4) + 5)
//what i want to express with bracket are the iterations.

And finally sum would store 15 in it.

But we need to initialize it before using. If we initialized with 1 or another instead of 0 the sum would have a different value - in this case 16.

#version Sum = 0
sum = 0 + (1+2+3+4+5)
= 15

#version sum = 1
sum = 1 + (1+2+3+4+5)
= 1 + 15
= 16

Hope you got it.

Answer 4

(first sorry if my english was bad)
Because, if you didn't assign number to your variable the compiler will generate random numbe
for ex: try defining int and then do cout for it like
int i;
cout<<i;
it will give you random number
for that when U define int sum u need to assign it value to 0 for the compiler don't give it random number and add it to the numbers your are calculating

more ex:
int number=5
sum=0
later you will
sum=number+sum
this mean:
0=0+5
this = 5
I hope U know now why we always put sum=0
and counter put it to 1;

Answer 5

the last explain is awesome,thanks very match👌🏻