Understanding this code

[zkl]

I have this code:

#include<iostream>
#include<iomanip>
using namespace std;

int main(){

for(int count=0; count<3; ++count){
int i=0;
while(i<10){
++i;
cout<<i;
}
cout<<endl;
}
return 0;
}

The output is:

12345678910
12345678910
12345678910

OK. I dont understand the code. I understand up to the point that it prints out 1 to 9. But why it print 10 since the condition is i<10 and also why it print 3 lines?

can someone explain this. Thanks

[Gulshan Singh]

It prints out 3 lines because the outer for loop goes from 0 to 2, which is 3 numbers.

Similarly, it prints out 10 number because it goes from 0 to 9, not from 1 to 9.

[Darkmaster]

for loop from 0 to 2: 3 lines
while loop from 0 to 9: adds 1 inside the loop, before the output. so you get a loop from 1 to 10

[zkl]

ok, now i get it.

0 is to be counted as 1 so when the condition is <3, it will be
0......1.......2 ----- 3 lines (it still met the condition as its <3)

Cool thnx.