Please explain these two doubts

#1

Why?

for(int i = 0 ;i <n ; i++)
{
arr[i] = new int[m];
}
is used?
&
What is the role of argv and argc in the main?

#2

to allocate 2D array of size MXN dynamically
first we make array of size M this will store address of n sized m arrays
int **arr=new int * [M]
now we make n sized m arrays

for(int i=0;i<m;i++){
  arr[i]=new int[n];
}

i hope this picture will help you to understand well

Screenshot from 2020-05-03 11-25-10

The variables are named argc (argument count) and argv (argument vector) by convention, but they can be given any valid identifier: int main ( int num_args, char arg_strings) is equally valid. They can also be omitted entirely, yielding int main () , if you do not intend to process command line arguments.

your doubt is very much similar to an another student you can check here also

#3

I think you missed one *.Should this be
int *arr = new int[M]
instead of
int *arr = new int[M]

#4

yes you are right
actually it is int ** arr=new int*[m]

it is error of editor it hide this

i have corrected now

if you have more doubts regarding this feel free to ask
if your doubt is resolved mark it as resolved from your doubt section inside your course

#5

if your doubt is resolved mark it as resolved from your doubt section inside your course

#6

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