Use of ArrayList in Java to store Name and Age

I want to add both String and Integer type of value in ArrayList.

For example i have array list in which i want to add name of the persons and age of the corresponding person in a single arralist.

How can i accomplish this. How can i get this? Actually i am retrievin开发者_Python百科g data from database and want to save all the employee names and ages in a single array list. Like multidimensional array list.

Create a a person class with age and name, then create an ArrayList of that type.

class Person {
  private String mName;
  private int mAge;
  public Person(int age, String name) {
     mName = name;
     mAge = age;
  }
  public String getName() {
     return mName;
  }
  etc ........
}

ArrayList<Person> arr = new ArrayList<Person>();
arr.add(new Person(10, "joe"));

You should create a class to represent a person and then add those to a list. It's a bad practice to mix the type of objects in a list. You could start with a simple person class:

class Person {
    private String name;
    private int age;

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }
}

Then create a list like this:

List<Person> people = new ArrayList<Person>();

And add people that you read from the database to the list:

people.add(new Person(name, age));

You can use the simple ArrayList and add the boxed type of int, Integer along with String.

You can make a Person Class

class Person{
 String name;
 int age;
 //Add the getteres and setters
}

Then declare an arrayList as follows.

ArrayList<Person> p = new ArrayList<Person>();

Then for each person create a person object and populate the arrayList as follows.

p.add(personObj);

You can create an ArrayList<Object>. Both Integer and String are subclasses of Object, and so both can be added to an ArrayList<Object>.

That said, it seems unlikely to me that you'd really want to do this. An ArrayList is a list. It's generally a bad smell (ie: a sign of a poor design) if you're storing things in a list that aren't the same kind of thing in some sense.

Having a correspondence between elements as you describe suggests that you actually want a list of employee objects, where each employee object has a name and an age.

Another possibility would be to use a Map if the names are unique. You can use a LinkedHashMap if you care about preserving order.

class Employee{
int age;
String name;
//+acessor method
}

Lit<Employee> list = new ArrayList<Employee>();

To make sure the compiler doesn't complain, use Generics to specify that you want to add Objects to your ArrayList; this will let you add both types Integer and String to it:

ArrayList<Object> myList = new ArrayList<Object>();

Then you can add your objects of either type to it.

However, Java is strongly-typed for a reason, so the need to add two types into one ArrayList suggests a design problem to me.