Question

My task in this lab is to accept multiple input file and the format is similar in all of them except that some files have comments and I want to skip the comments lines. For example:

Input file:

Input file 1

#comment: next 5 lines are are for to be placed in an array
blah 1
blah 2
blah 3 
blah 4
blah 5

#comment: next 2 line are to be placed in a different array
blah 1 
blah 2

#end of input file 1

---

What I tried doing was I used 2 while loops (I can post my code if needed). I did the following

while(s.hasNext()) {
    while(!(s.nextLine().startWith("#")) {
        //for loop used to put in array
        array[i] = s.nextLine();
    }
}

I feel like this should work but it does not. What am I doing incorrect. Please help. Thank you in advance.

Answer 1

There are two problems with your code:

1. You are invoking nextLine more than once within the loop.
2. Your second while loop will fail if there is no next line.

Try modifying code as follows:

int i = 0;
while(s.hasNextLine()) {
    String line = s.nextLine();
    if(!line.startWith("#")) {
          array[i++] = line;
    }    
}