Review for the test
 

• Loops
• Counting forward and backward by one or more

example:  Write me a loop that counts from 100 ... 1 by threes
• for, while and do loops
• If I give you a while/for loop, can you convert to the other kind?
• Infinite loops
• If-Thens
• Simple if-thens, and if-thens
• If-thens with elses
• Complex conditions

write me an if that prints "yes" if the variable 'age' is greater than 10 or the variable 'name' is Jenny Jones
you should know and, or, and not
you should know <,  <=, ==, >=, >, !=, and string.compareTo
• Remember that string compares do NOT use ==
• Files
• If a file is a text file or a binary file.
• How to open a file.
• How to read from a file.
• How to write to a file.
• What needs to go into the try block.
• When does the code in the catch block execute.
• Write me a program that copies a file.
• Write me a program that counts the number of lines in the file.
• Write me a program that prints "yes" if the file "fred.txt" exists
• Write me a program that prints "yes" is the file contains a line  that reads "to be or not to be".
• Simple array stuff
• Given an array, put this value in location 0, and push every thing down one.
• Remove the value at location 12, and move 13 ... up to fill the spot.
• Reverse the array (hard)
• Fill the array with the value '10'.
• Count the number of 3's in the array
• Find the biggest/smallest element in the array
• Sorting
• How does bubble sort work.
• How does selection sort work.
• How does merge sort work. (you don't need to code this, just understand it).
• Which is fastest/slowest.
• Be able to write either bubble or merge sort, or convert from one to the other.
• Know how to sort in reverse order
• Look at the code below.  Which kind of sort is it?  Will array[0] be the smallest or the largest element in the array?
• If it takes 10 seconds to sort a 1000 element list, and 40 seconds to sort a 2000 element list, could this be a merge sort?
•  Stacks
• Know how to code a stack.
• What are the basic operations of a stack?
• Suppose I push(4), push(12), push(3), pop(), pop(), and push(7). How many elements are currently on the stack?  What will the next pop give me?
• Does it take much longer to push a number onto a stack with 1,000,000 elements, or a stack with 10 elements.
• Look at the code below.  Notice the push() function.  Will that actually put a value on the stack, or is the push function broken?
• What happens when the stack is filled, and you try and push again?
• Queues
• What are the basic operations of a queue?
• Which is a better way to model an assembly line, a queue or a stack?
• Suppose I put 10 items onto a queue?  Which one comes out first?  Last?
• Know the circular buffer concept, and how modular arithmatic works.
• Know that normally, the buffer has one empty spot even when full.
• In the code below, what does the 'head' variable point to?

   Where the next item should be inserted
   Where the next item should be taken from
   One past where the next item to add should be inserted
   The first free spot ready for the next insertion
• Pointers
• What is a pointer?
• How do a declare a pointer to class foo?
• What happens when you dereference a null pointer?
• What happens when two things point to the same item, and you change a field of one of the pointers
• Recursive Programming
• What is a base case?
• What is a recursive case?
• Be able to code some basic recursive functions:  add,subtract, multiply, fibinachi
• Linked Lists
• What operations are linked lists good/bad at?
• Do linked lists take more space to store than an array?
• Know how to code the basic linked lists functions ... add/delete/max/min/count/search
• Binary Search
• What is it
• How fast is it
• Can you binary search on unsorted data?
• What kinds of data can you binary search on?
• Binary Search Tree
• What is it?
• What is the basic 'binary search tree property'?
• How would you declare a node for a binary search tree that held an integer named 'age'.
• You do not have to know how to code a binary search tree from scratch.  You might have to code a very easy function on a binary search tree.