I don't understand the answer

Question

What is the output of this code?
var result = 0;
for var i = 0; i < 5; i++ {
if i == 3 {
result += 10;
} else {
result += i;
}
}
print(result)

(the result is 17 but I dont understand why)

Answer 1

i = 0 => result += 0 => result = 0 + 0 = 0
i = 1 => result += 1 => result = 0 + 1 = 1
i = 2 => result += 2 => result = 1 + 2 = 3
i = 3 => result += 10 => result = 3 + 10 = 13
i = 4 => result += 4 => result = 13 + 4 = {17}

Answer 2

The loop will run 5 times until i = 5;

Loop one for i = 0 :
result = result + i;
result  = 0 + 0;
result  = 0;

Loop two for i = 1:
result = result + i;
result  = 0 + 1;
result = 1

Loop three for i = 2 :
result = result + i;
result  = 1 + 2;
result = 3;

Loop four for i = 3 :
result  = result + 10;
result = 3 + 10;
result  = 13;

Loop five for i = 4;
result  = result + i;
result  = 13 + 4;
result  = 17;

In  loop four for the if statement, when i == 3 we have to add 10 to the result.