用Java构造和使用Scanner

Question

I am looking at examples using Scanner to read a file (in Java). In one example, the Scanner was constructed using:

s = new Scanner(new BufferedReader(new FileReader("input.txt"))

But in another example the code is like below. My question is that is there something wrong with the way Scanner was declared below? Do we not need to use the s = new Scanner(new BufferedReader(new FileReader("input.txt")) constructor?

int howMany;
Scanner scan = null;
File f;
String[] words = null;

try {
    f = new File(filename);
    scan= new Scanner(f);
    howMany = scan.nextInt();
    words = new String[howMany];

    for (int i = 0; i < howMany; i++) {
        words[i] = scan.next();
    }
} catch (IOException e) {
    System.out.println(e);
}

Answer 1

There are multiple valid ways to construct a Scanner . Take a look at the documentation to see all of them.

There is nothing wrong with the approach that you have shown in your question.