Thread: Help with file I/O scanning etc

I have a program where a user enters a name and a gender, then the program is suppose to read through all these yob####.txt files to see if it contains that name,gender. if it does, i need to be able to get the number from it. in the yob####.txt files every single line is formatted like this "Mary,F,30045" the number is the number of times that name has been given to a baby for that year. I dont know how to get the number, i think i know how to find if it contains the Mary,F part but how do i get that number? heres my code:

package mat2670;
 
import java.util.*;
import java.io.*;
 
public class BabyNames {
 
    public static void main(String[] args) throws FileNotFoundException {
 
        //Set up the scanner to get a file
        Scanner console = new Scanner(System.in);
        System.out.print("Please enter a name:  ");
        String name = console.nextLine();
        System.out.print("Please enter a gender (M or F): ");
        String gender = console.nextLine();
        String genName = name + "," + gender;
 
        // Directory path here
        String path = "C:\\Users\\Connor Moore\\Documents\\yobdata";
 
        String files;
        File folder = new File(path);
        File[] Files = folder.listFiles();
 
        //loop to go through each file in the directory i have them in
        for (int i = 0; i < Files.length; i++) {
 
            Scanner nextFile = new Scanner(Files[i]);
 
            if (Files[i].isFile()) {
 
                while (nextFile.hasNextLine()) {
 
                    String nextLine = nextFile.nextLine();
 
                    if(nextLine.contains(genName)) {
 
                        //this is where im stuck, im not too sure how to get the number. from the string that contains the number i need.
 
                    }
                }
            }
        }
    }
}

well how i have it set up is what im searching the file for would be like this "Mary,F" and i already have the line that contains that as a string. How does this split method work?

So in the java docs i found this

String[] split(String regex)
Splits this string around matches of the given regular expression.

Trying to understand what it means, and how to implement it. So it might be easier to add the second comma to my genName so it has a string like "Mary,F," then if i do String[] number = split(genName); then would number have the numbers i need? and if so if there a method to convert those numbers from a string to an int, i have to work with the numbers as an int, keeping a running total, etc. thanks for the help btw

--- Update ---

I have this now, but the substring part is underlined, saying method : substring(int), variable numbers is of type String[]

                    if(nextLine.contains(genName)) {
 
                        String[] numbers = nextLine.split(genName);
                        int length = numbers.length;
                        System.out.println(numbers.substring(length));
                    }

arrays? where are arrays coming into this? you lost me now. and ok i found the method for the string to int conversion. still confused where arrays are coming into play at.. and if i try running my program now, it just starts endlessing print random stuff

Would something like this work.

                    if(nextLine.contains(genName)) {
 
                        int length = nextLine.length();
                        String numbers = nextLine.substring(length);
                        System.out.println(numbers);
                    }

--- Update ---

I mean it obviously doesnt work, because my output is just a lot of blank lines.. but could anything like that work? to me it looks like it would print the numbers after the "Mary,F," if the String its on is "Mary,F,12345"

--- Update ---

nvm, wow i just realized all im doing is getting the total length of the string that contains genName. ahhhh

--- Update ---

Ok, im making progress but im confused why im getting the brackets and the , in the output, heres the statement now, and the output

                    if(nextLine.contains(genName)) {
 
                        String[] numbers = nextLine.split(genName);
                        System.out.println(java.util.Arrays.toString(numbers));
                    }

Output:

Please enter a name:  Mary
Please enter a gender (M or F): F
Mary,F,  //this is what genName contains
[, 7065]
[, 6919]
[, 8149]
[, 8012]
[, 9217]
[, 9128]
[, 9891]

Ok i see how the split method works now, if i make a string like String tosplit = new String(","); and i use it in split, it just puts spaces in the string after the commas? I dont see how that could help me though? + it still gives me the [ ]'s

when i print the string there, the output gives me this [Mary, F, 1234]

                    if (nextLine.contains(genName)) {
 
                        String[] numbers = nextLine.split(tosplit);
                        String numbers2 = Arrays.toString(numbers);
                        System.out.println(numbers2);
                    }

Oh ok, so this is irrelevant, So still how am i extracting the data i need from the array that contains either [Mary, F, 1234] or how i had it as [, 1234]?

--- Update ---

Just wanted to add, that the length of the number can vary. its not always the same length

Ok, thank you very much for your help, I can now get the number with the strategy you have helped me with, I've got it converting to an int also that i can add to a running total.