从文件中读取两位数并避免使用空格/字符串（Java）

Question

I am trying to read from a file and add my numbers to an array. The file can contain white spaces and strings but I only need the digits.

0
4
xxx
52

23

Here is my code so far:

Scanner scanner = new Scanner(new File("file.txt"));
int i=0;
while(scanner.hasNextInt() && count < 15) {   //only need first 15 digits
    arr[i++] = scanner.nextInt();
    count+= 1;
}

The code currently works but it stops once it reaches a string or any whitespace.

Answer 1

Your while will quit when it hits the first non-integer. You need to change the condition:

// Loop until eof or 15 numbers
while(scanner.hasNext() && count < 15) {   //only need first 15 digits
    // Have a number?
    if (scanner.hasNextInt()) {
        arr[i++] = scanner.nextInt();
        count+= 1;
    }
    // Not a number, consume.
    else {
        scanner.nextLine();
    }
}

Answer 2

Try with this:

while (scanner.hasNext() && count < 15) { // use Scanner::hasNext 
    if (scanner.hasNextInt()) {           // if is number then add it to the array
        arr[i++] = scanner.nextInt();
        count++;
    } else {                             
        scanner.next();                   // else ignore the value
    }
}