0

Hey i got a program to get sum of digits but can't understand it .the commented one is the way I understand please explain other

num = int(input( )) sum = 0 while num > 0: # d = num%10 # num = num//10 #sum += d num,sum = num//10,sum+(num%10) print("The sum of digits of number is",sum)

3rd Nov 2018, 12:38 PM
partha
partha - avatar
4 Réponses
+ 5
Here's my best attempt on explaining this. Basically, num, sum = num//10, sum + (num%10) is the same as sum, num = sum + (num%10), num//10 and also the same as sum += num%10 num = num//10 but NOT the same as num = num//10 sum += num%10 Basically, on the oneliner shortcut, the calculations on the right side of the equal sign are calculated first before they are assigned to the variables. So, if the input is 123, num, sum = 12, 0+3 num, sum = 1, 3+2 num, sum = 0, 5+1 Therefore, after three iterations sum = 6. I hope that was clear. :)
3rd Nov 2018, 1:33 PM
Jonathan Pizarra (JS Challenger)
Jonathan Pizarra (JS Challenger) - avatar
+ 5
They are the same. var1, var2 = calculation1, calculation2 is the same as: var1 = calculation1 var2 = calculation2 num, sum = num//10, sum + (num%10) is the same as: num = num//10 sum = sum + (num%10)
3rd Nov 2018, 12:49 PM
Paul
Paul - avatar
+ 1
thanks a lot Jonathan Pizarra I guess my doubt was if on the left side first num's value is altered then sum would be too. Now it's all clear thanks again :-D:-D
3rd Nov 2018, 2:19 PM
partha
partha - avatar
0
thanks Paul Jacobs but there is still some doubt which I can't ask (cos I don't have proper words to ) can you please give an example using a number like 123? pls. :'(
3rd Nov 2018, 12:55 PM
partha
partha - avatar