Java: how do you write/read from a list which was returned from a method?

user_14190471 0
Viewed 64

I have an array and a method to create a list out of the values in the array.

    public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);    
    System.out.println("enter all names separated by commas");
    String allNames = scanner.nextLine();
    String[] letters = {"a", "b", "c", "d"};;
    convertToList(letters);       
}


public static ArrayList<String> convertToList(String [] array) { 
    ArrayList<String> outputList = new ArrayList<>();
    for (int i = 0; i<array.length; i++) {
        outputList.add(array[i]);
    }
    return outputList;
}

Now, if I wanted to print a string from outputList or add a new string to it in the main method, how do I do it?

java
4 Answers
ArrayList<String> myList = convertToList(letters);

And then you can read by using :

myList.get(index)
user_144917470 
public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);    
    System.out.println("enter all names separated by commas");
    String allNames = scanner.nextLine();
    String[] letters = {"a", "b", "c", "d"};

    ArrayList<String> myList = convertToList(letters);
    // prints "a"
    System.out.println(myList.get(0));
    // add
    myList.add("e");
}
user_102252990

You can use ArrayList as return type is ArrayList for given method

    ArrayList<String> list = convertToList(letters); 
    list.get(0); //a
    list.add("e"); //add another string
    System.out.println(list); //output:- a b c d e f
user_120797190 
public class Foo {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        System.out.println("enter all names separated by commas");
        List<String> names = convertToList(scan.nextLine().split(","));

        System.out.println();
        print(names);

        names.add("John Doe");
        System.out.println();
        print(names);
    }

    public static List<String> convertToList(String[] names) {
        return Arrays.asList(names);
    }

    private static void print(List<String> names) {
        for (String name : names)
            System.out.println(name);
    }

}
user_34613970
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