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Please explain how the looping works in this program

#include<iostream> using namespace std; int main (){ for (int i=1;i<=5;i++){ for (int j=5;j>=i;j--) cout<<"*"; cout<<endl; } return 0; }

23rd Nov 2016, 3:43 AM
rizzmae98
2 odpowiedzi
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the best way to see how the loop variables change is to print out their values inside the loop, for example #include <iostream> using namespace std; int main() { for(int i=1; i<=5; i++){ for(int j=5; j>=i; j--){ cout << i << ", " << j << endl; } } return 0; } and analyze the output. you should notice that this is what happens: 1. i=1 (outer loop). check i<=5 (1<=5 - true). enter inner loop. a. j=5 (inner loop). check if j>=i (5>=1); since the condition is true, we enter the loop and print '*' b. j=4 (inner loop). again check j>=i (4>=1 - true), enter the loop and print '*' c. j=3. repeat steps above ...... f. j=0 (inner loop). check j>=i (0>=1 - false). we exit from inner, back to outer loop. 2. i=2 (outer loop). check i<=5 (2<=5 - true). we enter the inner loop. a. j=5 (inner loop). check j>=i (5>=2 - true). enter loop and print '*' b. j=4. repeat steps as above. ...... e. j=1. check j>=i (1>=2 - false). back to outer loop. 3. i=3. repeat steps as above. ....... 6. i=6. check i<=5 (6<=5 - false). we exit from the whole loop.
23rd Nov 2016, 5:01 AM
Rill Chritty
Rill Chritty - avatar
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thank you so much for your help
29th Nov 2016, 3:16 AM
rizzmae98