Module 15 Programming and Scripting
MVC
- a development technique used in the implementation of user interfaces - separates the user interface into different components
Model Layer
- can take on different forms - an actual object that is an actual implementation of the application - where the business logic is designed
Hexadecimal
- composed of chunks of 4 binary numbers to make binary easier to read - 64 bits (8 bytes) - (base 16) - can represent any number using 16 digits 0 -9 and A-F
Octal
- group binary into chunks of 3 to make reading and storing easier. - 32 bits (4 bytes) - (base 8) - can represent any number using 8 digits 0 -7
The logic tier
- resides on the organization's servers - a conduit through which the data flows to the user from the databases as well as how data input from the user is used to update the underlying records in the database. - where the system performs its logic processing
Controller Layer
- the part of an application that interacts with the user (via the view) and passes along the user requests to the model - where the input logic is designed
data tier
-resides on the organization's servers and usually on a separate database server -where data are stored, retrieved, and updated from database tables
Text - 1 character =
1 byte
Two common forms of character representation
ASCII (American Standard Code for Information Interchange) and Unicode
Most common high-level languages used to write programs
Basic C C++ Java Python FORTRAN Ada Pascal
Digital system
Binary Information is stored in one of two ways Current or No Current
The ______ was a major factor in the development of scripting languages because they _____
Internet, commonly add functionality to a Web page by influencing the data that the user sees in a browser window
The most distinct difference between interpreted and compiled programming...
Interpreted programming is more experimental in nature and developing a program can be done in a piecemeal manner. Compiled programming often requires that the entire program be written before any of it can be compiled and tested.
Most common scripting Languages
JavaScript ASP JSP PHP Perl Tcl Python
MVC stands for
Model-View-Controller
Interpreter
Takes the most recently entered instruction, translates it into machine language, and executes it.
What is the difference between the MVC model and N-tier development model?
The MVC model is one application where the various design logic (input, business and interface) are logically separated. This differs from the n-tier development model where each tier is a separate application
Compiler
Translates the entire program, creating an executable program, which can be run at a later time.
bit
a single 1 or 0 value
Advantage of a interpreted language
allows the programmer to experiment while developing code
script
an interpreted program that is typically fairly short and the instructions are relatively simple (as compared to applications or systems software).
When writing an algorithm one should strive to make it ____.
as clear and simple as possible
Translators for each type of languages are
assembly compilers interpreters
3 Types of language translators
assembly languages high-level compiled languages high-level interpreted languages
Scripts have traditionally been used for____ rather than for _____
automation, software development
Decimal system
base 10 - can represent every number with some combination of 10 digits (0-9)
Binary System
base 2 - can represent any number using 2 digits 0 or 1
A program written in a high-level language must be _____ to be executed by the computer
converted into machine code
JavaScript
designed to be used inside a web browser environment
Disadvantage to interpreted programming
every instruction is translated first and then executed; this must be done every time the program is run whereas once a program is compiled, the chore of translation is over.
algorithm
is a formula or procedure for solving a problem.. more specifically, a set of steps that are followed in order to complete a computer process
The presentation tier
is where the user interface for the system is developed.
A disadvantage of a compiled language
it is not portable it is translated into machine code that is compatible with a specific type of computer. The program itself is portable in that it can be compiled differently for different computers.
language translator
program that takes one program, written in a high-level language, as input, and creates a machine language program as output.
Scripting languages
specific interpreted programming languages
n-tier development is often used to indicate what?
that the number of tiers a system will be broken down into will vary between different software development projects
MVC components are...
the model, the view, and the controller.
In typical n-tier development projects, the tiers are divided between
the presentation tier, the logic tier, and the data tier
View Layer
user interface
Programming language
vocabulary and set of rules for instructing a computer to perform certain tasks
