I really don’t understand exrcicses 3 on control flow, the code says o - 6 because i is 0 at first and 6 is n. But then there is only 5 spaces printed out? why?
Course: Learn C from Scratch - Learn Interactively
Lesson: Exercises on Control Flow - Learn C from Scratch
Hi @A_Huang, Thanks for reaching out to us.
The following for loop and variable j is responsible for printing the space:
for (j=0; j<(n-i); j++)
{
printf(" ");
}
Now let’s consider the 6th iteration and value of n=6 when space is not printed
j<(n-i) -----> 6< 6-6 -----> 6<0 -----> False
The spaces are not printed at the 6th iteration because the condition j<(n-i) in the for loop is false and print(" ") not executes at this time.
Hope it will clear your confusion, Happy Learning 
So it’s 0< 6, 1 < 6, 2 <6, 3 < 6, 4 < 6, 5 < 6, 6 <6(false). But then there are still 6? I’m happy to see replys but I still don’t understand
Course: Learn C from Scratch - Learn Interactively
Lesson: Exercises on Control Flow - Learn C from Scratch
for (j=0; j<(n-i); j++) { printf(" "); }
Hi @A_Huang, Thanks for reaching out. Each line of the pattern carries spaces, if we consider the first line there are 5 spaces.
Condition for first-line: 0<6, ––> 5 spaces
Condition for second-line: 0<5, ––> 4 spaces
Condition for third-line:0<4, ––> 3 spaces
Condition for fourth-line:0<3, ––> 2 spaces
Condition for fifth-line:0<2, ––> 1 spaces
Condition for sixth-line:0<1, ––> 0 spaces
0<0 ––> Condition false