关于Java中的ArrayList

Question

I want to add some different types elements into the same index in ArrayList.For example:

List account= new ArrayList();
        String name;
        int number;
        float money;
        account.add(0,name);
        account.add(1,number); 
        account.add(2,money);

But now , i want to take String name , int number and float money save into the same index.How to do it ?If Arraylist can't. How can i do act this function?

Answer 1

i want to take String name , int number and float money save into the same index.How to do it ?

You should create a model class named Account . Than define a list like List<Account> .

 class Account{
  String name;
  int number;
  float money;
  // Constructor, Getter setter etc..... 
 }

 List<Account> list= new ArrayList<Account>();
 list.add(new Account("Name", 123, 50.0));     

Than, account information will be at account instance at same index. You can access the Account data using list.get(index) method.

Answer 2

Alexis C. is right (in the question's comments). You'll have to use a class to represents what is an account. Then you'll be able to create instances of this class for all accounts. Example :

class Account {
  String name;
  int number;
  float money;

  Account(String name, int number, float money) {
    this.name = name;
    this.number = number;
    this.money = money;
  }

}

// And somewhere else you'll want to use that class : 
List<Account> accounts = new ArrayList<>();
account.add(new Account("Account1", 1, 1f));
account.add(new Account("Account2", 2, 2f));
account.add(new Account("Account3", 3, 3f));

I suggest you to consider learning basic object oriented programming (ie:Composition, Inheritance, Polymorphism)

Hope this example help.

PS : In a real life application, I would recommend the use of the BigDecimal class to handle money, as float (and double) have precision problems.