为什么不读取while语句？

Question

I have a .dat file with the following information:

Erik 3 Rita 7 Tanner 14 Jillyn 13 Curtis 4 Stephanie 12 Ben 6

It reads boy's name, boys age, girl's name , girl's age etc.

I have to count the total number of boys and total number of girls, then add the ages of the boys and the ages of the girls, then find the difference between them (Absolute).

I have created the following code to do this:

public class Exercise1 {
public static void main(String[] args) 
    throws FileNotFoundException {
    Scanner input = new Scanner(new File(
            "C:/FilesForJava/ChapterSixExerciseOne.dat"));
    boyGirl(input);     
}
public static void boyGirl(Scanner fileInput) {
    int boysCount = 0, girlsCount = 0, counter = 1,
            boysSum = 0, girlsSum = 0;
    while(fileInput.hasNext()){         
        if(counter % 2 != 0) {
            boysCount++;
        }
        else {
            girlsCount++;
        }
        while(fileInput.hasNextInt()) {
            if(counter % 2 != 0) {
                boysSum += fileInput.nextInt();
            }
            else {
                girlsSum += fileInput.nextInt();;
            }           
        }
        counter++;
    }
    System.out.println(boysCount + "Boys, " + girlsCount + "Girls");
    System.out.println("Difference between boys' and girls' sums: " + Math.abs(boysSum - girlsSum));
}

The problem is that the program never enters the nested while statement and I can't figure out what I am doing wrong. Not only does it always bypass it, the first while statement never ends so it perpetually loops. The book uses .dat files in their examples. I used notepad to create the file and saved it as a .dat file. Could this be my problem?

Please advise.

Answer 1

fileInput.hasNext() must be followed by next() , so that the token is consumed and the file moves forward.

Otherwise, the file position is always the begining, and there is always a next token ('Erik'), and never a next int.

Typically, I would:

while(fileInput.hasNext()){
    System.out.println("Kid's name: " + fileInput.next());
    // Rest of your code