Why this is an infinite loop?

Question

Why the loop goes on to infinity , I have put limits via n<6 , one more thing , the code prints 111111... . The output that I expect is 12345.

#include <stdio.h>

//Compiler version gcc  6.3.0

int main()
{
  int n=1;
  do{
    while(n<6)
    printf("%d",n);
    n++;
  }
  while(n<6);

  return 0;
}

Answer 1

Why this is an infinite loop?

Because this:

do{
    while(n<6)
    printf("%d",n);
    n++;
}
...

Is actually this:

do{
    while(n<6) {
        printf("%d",n);
    }
    n++;
}
...

The code will never escape the "single statement while loop" just under the do. I would suggest that deleting it so that you only have one line that says while(n<6), just above the return, will make your program function as you expect