declaring ArrayList in java Constructor

I am working on a project, and I was taught to instantiate variables in constructors. I'm having some trouble doing this with an ArrayList thought. Can you suggest some best practices, do I need to define the ArrayList with the instance variables or can I do it in the constructor. Thanks for your suggestions! I have an example of what I'm talking about below: ``` //imports import java.util.*; import java.lang.*; public class ArrayListConstructorDemo { //instance variables/attributes String string; List<String> list;// for example does this line need to say List<String> list = new ArrayList<String>(); //constructors public ArrayListConstructorDemo() { String string = "null"; List<String> list = new ArrayList<String>();//is there anyway I can do this here instead of 6 lines up? }//end default constructor public ArrayListConstructorDemo(String string,List<String> list) { this.string = string; this.list = list; }//end generic constructor //observers/getters/accessors public String getString(){return string;}//end method getString() public List<String> getList(){return list;}//end method getList() //transformers/setters/mutators public void setTable(String string){this.string = string;} public void setValues(String list) { // for(String s : test) // { list.add(this.list); // } } public String toString() { return "this is a generic toString method for the class ArrayListConstructorDemo"; }//end toString public static void main(String[] args) { ArrayListConstructorDemo alcd = new ArrayListConstructorDemo(); System.out.println(alcd.list.size()); //test Lists in general List<String> bleh = new ArrayList<String>(); bleh.add("b1"); System.out.println(bleh.get(0)); }//end method main() }//end class ArrayListConstructorDemo ```