Why would a for loop use subtraction instead of an absolute number?

Question

If you come across a code with a for loop that does something similar to the code below, why do you think a subtraction is used instead of an absolute number?

for (int i = 0; i < 3 - 1; i++)
{
//some code
}

Answer 1

To make people understand it more.

e.g.

//sum of all elements up to the 50th
for(int i = 0; i < 50 -1; i++);

Is easily understandable than
for(int i= 0; i < 49; i++);

Answer 2

In Python I discovered that - operator required little more runtime than + operator, thus I would use:
for (int i = 0; i + 1 < 3; i++) {}

To save few nanoseconds from your life.

Answer 3

Seb TheS That is not a valid Python program 😐

Answer 4

Yes. Just for understanding.. Otherwise better to use 2 in place 3-1 for to have one less calculation..