读取文本文件并添加到数组，但跳过特定部分（Java）

Question

I have a text file which I want to extract floats from and add to an array, but I keep getting an error and I'm not sure how to solve it. It's to do with the string (the x and y), but I'm not sure how to skip these and only add the floats to the array.

My txt file:

x, 19.0
y, 22.5

My code:

public static void readParameters() throws FileNotFoundException{
    Scanner inFile = new Scanner(new File(filename));
    ArrayList<Float> values = new ArrayList<Float>();
    
    while (inFile.hasNextLine()) {
        String line = inFile.nextLine();
        String[] nums = line.trim().split("\\s+");
        for (String num : nums) {
            float token = Float.parseFloat(num);
            values.add(token);
            System.out.println(nums);
        }
    }

    inFile.close();
}

Overall, I want my array to just have the two floats.

Answer 1

The split("\\s+") will return an array which contains values like ["x,", "19.0"] for first row. As you are trying to convert non-float value x, to float its throwing exception.

Please try below code:

    public static void readParameters() throws FileNotFoundException{
        Scanner inFile = new Scanner(new File(filename));
        ArrayList<Float> values = new ArrayList<Float>();

        while (inFile.hasNextLine()) {
            String line = inFile.nextLine();
            String[] nums = line.trim().split("\\s+");
            if(nums.length == 2 ) {
                float token = Float.parseFloat(nums[1]);
                values.add(token);
                System.out.println(nums);
            }
        }

        inFile.close();
    }