How to create a contact list in Java?
The assignment is to create a contact list that uses inheritance, polymorphism,and collections. I need a contact list that stores two types of contacts: business and personal. I need prompt 1 to add a contact and then ask 1 for personal or 2 for business.
Is the contactlist the superclass object of type contact?
It looks like your contactList is in fact the superclass object of type Contact, and with that said you will not be able to access the methods/attributes of the subclass because it doesn’t know about them, and I imagine you have tried but it will tell you symbol not found I believe.
How to create an ArrayList Challange in Java?
Available actions: press 0 – to shutDown 1 – to print contacts 2 – to add a new contact 3 – to update an existing contact 4 – to remove and existing contact 5 – query for existing contact 6 – to print a list of available actions.
How to create a program using ArrayList in Java?
So we will learn step by step how to Create a program that implements a simple mobile phone Contacts Option Using ArrayList in Java. Step 1: Create Contacts.java System.out.println(“You have ” + contactList.size() + ” Contacts in your list.”); Step 2: Create MobilePhone.java All the method implementation we will do in this class.
I need a contact list that is stores two types of contacts: business and personal. 1. Prompt to select which contact to add or display. 2. Prompt to allow user to enter the contact info. 3. Prompt that will display the output of a chosen contact back. I have the following class and subclasses.
Why are optional objects introduced in Java 8?
According to the Oracle documentation, an Optional is a container object that may or may not contain a non-null value. It was introduced in Java 8 to cure the curse of NullPointerExceptions.
How to use optional in Java 8 best practices?
Java 8 Optional Usage and Best Practices 1 Life Before Optional. Before Java 8, programmers would return null instead of Optional. 2 Features of Optional. The optional class provides around 10 methods, which we can use for creating and using the Optional class and we are going to see how they are 3 Best Practices for Using Optional.
Can you have an array of list in C #?
You have to create lists and put in the array, for example: Since no context was given to this question and you are a relatively new user, I want to make sure that you are aware that you can have a list of lists. It’s not the same as array of list and you asked specifically for that, but nevertheless:
How to create array of list in Stack Overflow?
I can suggest that you both create and initialize your array at the same line using linq: Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. Provide details and share your research! But avoid … Asking for help, clarification, or responding to other answers.
Is the array of list the same as the array?
It’s not the same as array of list and you asked specifically for that, but nevertheless: You still would have to allocate each individual list in the array before you can use it though: I can suggest that you both create and initialize your array at the same line using linq: Thanks for contributing an answer to Stack Overflow!