Java method to find a name variable starting with a given string from an ArrayList

Question

I have made an ArrayList.txt which contains a list of students with their grades, a separate class student containing getName(), getGrade(), getMarks() etc and on my main class, I have a main method which will pull from this method

Hence my method goes as this:

public static String findName(ArrayList<Student> o, String name) {

    for(int i = 0; i < o.size(); i++)
    {
        if(o.get(i).getName().startsWith(name.toLowerCase()))
            System.out.print(o.get(i));
    }
    return name;
}

and my main method has this findName(students, "al");

my array.txt looks something like this

afafwafa
B
80
alicegg
C
70
lfhif
D
50
Allllleeee
A
94

however my findName() method is unable to pull all names that starts with "al" even though all my other methods are working. Also I need to take note that the method should be case insensitive and i need to use .startsWith(). Any suggestions?

To add on, with the given ArrayList of type student with a string file name, i need to create a method that will write the members of the arraylist to a text file with a given name with 1 element to a line using student class toString method format. i need to handle possible exceptions with try/catch. I also need to use either filereader, fileoutputsteam, printwriter, printstream in the code

public static void nameToFile(ArrayList<Student> a, String file) {      

    int i = inone.read();
    FileReader inone = new FileReader(a.get(i).toString());
    FileOutputStream fos = new FileOutputStream(file);
    PrintWriter outone = new PrintWriter(fos);

    outone.close();
 }

my main method has this

nameToFile(students2,"modified.txt");

Put a toLowerCase() after getName() too?

Kayaman
– Kayaman

2017-02-28 19:02:40 +00:00
Commented Feb 28, 2017 at 19:02 — Kayaman
– Kayaman, Commented Feb 28, 2017 at 19:02

user3437460 · Accepted Answer · 2017-02-28 19:03:30Z

2

Also i need to take note that the method should be case insensitive and i need to use .startsWith().

If you want your startsWith() method to ignore the case, just convert both to lower or upper case before comparison:

if(o.get(i).getName().toLowerCase().startsWith(name.toLowerCase()))

If your findName() is supposed to just return 1 name, you can return it in the if-condition. If you want to return a list of names, add it to another arraylist, then return the arraylist.

answered Feb 28, 2017 at 19:03

user3437460

17.5k18 gold badges67 silver badges110 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Fin Fin Over a year ago

adding a toLowerCase works! wow i did not realise it was that simple. thanks! as for writing member of ArrayList to a text file, any suggestions?

Jason C Over a year ago

An alternative that I never feel gets enough credit is o.get(i).getName().regionMatches(true, 0, name, 0, name.length()).

Jason C Over a year ago

@FinFin For writing you've got all the methods of PrintWriter at your disposal. Note that System.out is a PrintWriter as well so you may already be familiar with the interface. You appear to be opening the output file correctly, all that's left is to print[ln] to your heart's content for each item you want to write, then close the file.

Collectives™ on Stack Overflow

Java method to find a name variable starting with a given string from an ArrayList

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related