+ 4

Nested loop question

Hi Guys, I have a problem with this nested loop and how it works, whats the logic here... var count = 0; for(var i = 0; i < 3; i++){ count--; for(var j = 0; j <= 2; j++){ count++; } } console.log(count); // Outputs 6

10th Jul 2020, 6:07 PM
David
David - avatar
5 Answers
+ 12
David First iteration: Count-- //which is post-operative i.e means value will decrement after use. So value of count entering in j loop is 0 After complete iteration of j loop: Final value of count = 3 But before next iteration of i loop it decreases by one according post-operative operation. Count = 2 This cycle continues for next 2 iterations And final value of count = 6.
10th Jul 2020, 6:16 PM
Ketan [#Be Happy 😄]
Ketan [#Be Happy 😄] - avatar
+ 6
When ,outer for loop runs for 1st time , count =-1, then Three time inner loop runs for , three time then count = -1+1+1+1 =2 Then again outer for loop runs for second time then Count =2-1=1 Then inner loop 3 times Count=1+1+1+1=4 Then outer loop for last time Count=4-1=3 Then inner loop 3 l of st time Count=3+1+1+1=6 Is this clear
10th Jul 2020, 6:19 PM
Raj Kalash Tiwari
Raj Kalash Tiwari - avatar
+ 4
the count first decremented once and then incremented thrice inside the inner loop.. and all of those repeated 3 times so, count in 1st loop = -1. 0, 1, 2 2nd loop = 1, 2, 3, 4 3rd loop = 3, 4, 5, 6
10th Jul 2020, 6:17 PM
durian
durian - avatar
+ 4
David 📍The first loop is repeated 3 times.. (from i= 0 to 2) 📍For each i repetition count is decreased by 1 and the second loop is repeated 3 times (from j=0 to 2) 📍In each time count is increased by 1. 📍So count initial value is 0 then we go into the first loop (count become - 1) then enter the second loop and increase by 1 three times and become 2.. Go into the first loop again and repeart the steps decrease by one then increase by 1 three times and you get 4.. And in the last itration for the first loop you finally get count =6.. I hope my explanation is clear.. 😁
10th Jul 2020, 6:18 PM
Salma Hashim
Salma Hashim - avatar
+ 3
Thank you all for your help! You all explained it pretty good
10th Jul 2020, 11:44 PM
David
David - avatar