Can you explain how scanner works? Does it print everything?

manpreet Best Answer 3 years ago

I was trying to understand how scanner worked so I tied to scan in a text document and iterate only through certain words but it didn't work, it just printed everything. So i replaced it with a loop that just printed numbers but it never even printed it and it printed all the words in the text document even though I didn't write a print statement for that. Does scanner just automatically print everything? How come my for loop is being skipped too?

    Scanner read=new Scanner(new File("Test.txt"));
    read.close();
    for(int i=0; i<5; i++) {
        System.out.println(i);
    }

manpreet 3 years ago

Please modify your code to this :

Generic Code :

Scanner reader = new Scanner(new File("Test.txt"));
while (reader.hasNext()){
   String str = reader.nextLine();
   System.out.println(str);
}

reader.close();

For reading integers :

Scanner reader = new Scanner(new File("Test.txt"));
     while (reader.hasNext()){
       int i = reader.nextInt();
       System.out.println(i);
    }

reader.close();