Method with name of class, no return type, use to initialize the state of objects. 

Constructors assign parameter values to instance variables, cause memory to be allocated (behind the scenes) to store those values.  

We can have more than one constructor.

See String227 append and the growArray method in Chapter 10

See String227 insertCharAt

In general, find an insertion spot, move all element right by one index beginning at the end--move index from n down to insertion spot.

A type like String except there are methods that change the state. 

A class that allows objects to remember a collection of characters. 

Some methods return state, other modify the Stirng227

Scanner will only be on the test with a string argument in the constructor. 

It mimics input from an input stream such as the keyboard or an input file.

Be careful to use next, nextInt and nextDouble only once in a loop. Store the next value into a local variable.

Variables declared in the class, but not locally in any method 

Values the objects remembers. They are needed by objects to be able to do what they are supposed to

Used to verify your code works (could also use printlns for small problems)

So far we only need these:

   assertEquals(anyType expected, sameType actual)

   assertTrue(boolean)
   assertFalse(boolean)