Order of if-else blocks | Sololearn: Learn to code for FREE!
New course! Every coder should learn Generative AI!
Try a free lesson
+ 1

Order of if-else blocks

Would it make any difference or have any impact on performance if I switched those 2 if blocks? if (i % 3 == 0) { cout << "Fizz" << endl; } else if (i % 5 == 0) { cout << "Buzz" << endl; } I know it's not a question worth asking, but I'm wondering if the program would run slightly slower if 5 is checked first because it's greater than 3 https://code.sololearn.com/ca63KT1dN2Q3/?ref=app

3rd Oct 2021, 7:06 PM
Tim
Tim - avatar
2 Answers
+ 2
The if condition is always checked, the else if condition only when the if condition is false. So how many times the else if condition has to be checked depends on the false ratio of the if condition. The higher the ratio the more often the else if condition has to be checked. For i % 3 == 0 that ratio is 2/3. For i % 5 == 0 that ratio is 4/5. So the order you used is slightly more efficient than the alternative.
3rd Oct 2021, 8:13 PM
Simon Sauter
Simon Sauter - avatar
+ 1
Simon Sauter Thanks for the clarity!
4th Oct 2021, 12:48 AM
Tim
Tim - avatar