Java：int数组返回为0

Question

I'm trying to pull an array from a text file (see radiation[] below), but it keeps returning zeroes. I'm happy to provide the .txt. file.

The text file I'm using has a range of integers from 1-200 (the first is 16), but the code appears to be reading the file as all zeroes. Any ideas about what's going on with this? Thanks for the insights!

public static void main (String[] args) {

    int radCtr = 0;
    Scanner scanner = new Scanner(new File("C:/Users/u23s57/Documents/4_22_18_radiation.txt"));
    while (scanner.hasNextLine()) {
        radCtr++;
        scanner.nextLine();
        }
    int [] radiation = new int [radCtr]; 
    int i = 0;
    while(scanner.hasNextInt()){
       radiation[i++] = scanner.nextInt();
    }

    for (int y = 0; y < radiation.length; y++) {
        System.out.println(radiation[y]);

        }
    int max = getMax(radiation);
    System.out.println("Maximum Value is: "+max);

    }

Answer 1

while (scanner.hasNextLine()) {
    radCtr++;
    scanner.nextLine();
    }

This loop consumes all the lines in the file. So when you get to here:

while(scanner.hasNextInt()){

There are no more ints to read.

You either have to:

• Re-open the scanner after the first loop.
• Allocate an array of arbitrary size (that is at least as large as it needs to be)
• Use a data structure that you don't need to know the size of in advance (eg a List ).
• Do it without storing all the data. You don't need to store it all to get the maximum.

Answer 2

Because of "scanner.hasNextLine()" you don't have any integers left anymore. Therefore, you should use different scanners.

Just another thing, it might be better to not use the scanner but bufferedreader. In my opinion especially when you're going to use delimiter (which i don't see yet though)