Unit 7 Vocabulary

Autoboxing

• Automatically wrapping a primitive type in a wrapper class object. For instance if you try to add an int value to a list, it will automatically be converted to an Integer object.
• To get an object at an index from a list use listName.get(index).
• Automatically converting a wrapper object like an Integer into a primitive type such as an int.
• To declare an ArrayList use ArrayList name, where Type is the class name for the type of objects in the list. If you leave off the it will default to Object.

Abstract Method

• A method that only has a declaration and no method body (no code inside the method).
• An ArrayList can hold many objects of the same type. It can grow or shrink as needed. You can add and remove items at any index.
• Automatically converting a wrapper object like an Integer into a primitive type such as an int.
• Use listName.size() to get the number of objects in the list.

ArrayList

• To create an ArrayList use new ArrayList, where Type is the class name for the type of objects you want to store in the list. There are other classes that implement the List interface, but you only need to know the ArrayList class for the exam.
• An ArrayList can hold many objects of the same type. It can grow or shrink as needed. You can add and remove items at any index.
• To set the value at an index in a list use listName.set(index,obj).
• To declare an ArrayList use ArrayList name, where Type is the class name for the type of objects in the list. If you leave off the it will default to Object.

Add

• To declare an ArrayList use ArrayList name, where Type is the class name for the type of objects in the list. If you leave off the it will default to Object.
• A method that only has a declaration and no method body (no code inside the method).
• You can access and set values in a list using an index. The first element in a list called list1 is at index 0 list1.get(0). The last element in a list is at the length minus one - list1[list1.size() - 1].
• You can add an object to the end of a list using listName.add(obj). You can add an object at an index of a list using add(index,obj). This will first move any objects at that index or higher to the right one position to make room for the new object.

Declaration

• You can access and set values in a list using an index. The first element in a list called list1 is at index 0 list1.get(0). The last element in a list is at the length minus one - list1[list1.size() - 1].
• Automatically converting a wrapper object like an Integer into a primitive type such as an int.
• To declare an ArrayList use ArrayList name, where Type is the class name for the type of objects in the list. If you leave off the it will default to Object.
• You can add an object to the end of a list using listName.add(obj). You can add an object at an index of a list using add(index,obj). This will first move any objects at that index or higher to the right one position to make room for the new object.

Creation

• You can access and set values in a list using an index. The first element in a list called list1 is at index 0 list1.get(0). The last element in a list is at the length minus one - list1[list1.size() - 1].
• To create an ArrayList use new ArrayList, where Type is the class name for the type of objects you want to store in the list. There are other classes that implement the List interface, but you only need to know the ArrayList class for the exam.
• To set the value at an index in a list use listName.set(index,obj).
• Automatically wrapping a primitive type in a wrapper class object. For instance if you try to add an int value to a list, it will automatically be converted to an Integer object.

Get

• To get an object at an index from a list use listName.get(index).
• A method that only has a declaration and no method body (no code inside the method).
• You can add an object to the end of a list using listName.add(obj). You can add an object at an index of a list using add(index,obj). This will first move any objects at that index or higher to the right one position to make room for the new object.
• Automatically converting a wrapper object like an Integer into a primitive type such as an int.

Index

• Use listName.size() to get the number of objects in the list.
• You can access and set values in a list using an index. The first element in a list called list1 is at index 0 list1.get(0). The last element in a list is at the length minus one - list1[list1.size() - 1].
• To declare an ArrayList use ArrayList name, where Type is the class name for the type of objects in the list. If you leave off the it will default to Object.
• To get an object at an index from a list use listName.get(index).

Remove

• To create an ArrayList use new ArrayList, where Type is the class name for the type of objects you want to store in the list. There are other classes that implement the List interface, but you only need to know the ArrayList class for the exam.
• To get an object at an index from a list use listName.get(index).
• To set the value at an index in a list use listName.set(index,obj).
• To remove the object at an index use ListName.remove(index). This will move all object past that index to the left one index.

Set

• A method that only has a declaration and no method body (no code inside the method).
• To get an object at an index from a list use listName.get(index).
• Automatically wrapping a primitive type in a wrapper class object. For instance if you try to add an int value to a list, it will automatically be converted to an Integer object.
• To set the value at an index in a list use listName.set(index,obj).