Chapter 1 intro to computers and programming Flashcards
5 main hardware components
CPU, Main memory(ram), secondary memory(hdd), input devices, output devices.
CPU(central processing unit) parts(1of2)
control unit which retrieves and decodes program instructions, coordinates activities of all other parts of computer.
cpu part 2of2
ALU: arithmetic and logic unit: Hardware optimized for high-speed numeric calculation
Hardware designed for true/false, yes/no decisions
main memory properties
volatile, erased when loses power or program terminates. called random access memory(RAM), made of bits(1 or 0) and bytes(group of 8 consecutive bits, byes haves addresses)
secondary storage properties and types
non-volatile,keeps its memory when shut off.
magnetic: floppy, hard drive
optical: cd, dvd
flash: usb drives
Types of software
system software and application software
system software
programs that manage the computer hardware and the programs that run on them. includes operating systems, utility programs and software development tools
application software
programs that provide service to the user such as word processors, games, specific problem solving programs
program
a set of instructions that the computer follows to perform a task
algorithm
a set of well-defined steps.
machine language
binary instructions that the machine can understand.
programming language types
low such as machine code(binary) and high level such as C++ that are closer to human readability.
steps from high level language to executable
- write source code
2.Run preprocessor to convert source file directives to source code program statements.
3.Run compiler to convert source program into machine instructions.
4.Run linker to connect hardware-specific code to machine instructions, producing an executable file.
steps 2-4 often occur with a single click.
IDE?
An integrated development environment, or IDE, combine all the tools needed to write, compile, and debug a program into a single software application.
common elements in programming languages
Key Words Programmer-Defined Identifiers Operators Punctuation Syntax
keywords
aka reserved words, commands in a programming language that are reserved and cannot be used in variables names, etc.
Programmer-defined identifiers
names made by programmer, not part of language(C++)
used to represent variables(memory locations), functions, etc.
operaters
used to perform operations on data
includes arithmetic +,-,*,/
and assignment =
punctuation
characters that mark the end of a statement such as , and ;
syntax
The rules of grammar that must be followed when writing a program
Controls the use of key words, operators, programmer-defined symbols, and punctuation
variable
A variable is a named storage location in the computer’s memory for holding a piece of data.
variable definition(declaration?)
To create a variable in a program you must write a variable definition (also called a variable declaration)
variable types
many different types each holding a specific amount of data
general steps of a program
(planning),input, processing, output
programming process
- define what a program should do
2.visualize the program running on a computer
3.use design tools like flowcharts, hierarchy charts and pseudocode to to create a model of the program
4.check model for logical errors
5.type code, save, compile
6.check for errors found in compilation repeat 5 and 6 as necessary
7.run program with test input
8.correct any errors found in running algorithm
repeat 5-8 as necessary
9.validate results of program
Procedural vs object oriented programming
Procedural programming: focus is on the process. Procedures/functions are written to process data.
Object-Oriented programming: focus is on objects, which contain data and the means to manipulate the data. Messages sent to objects to perform operations.
Four steps to identify when defining what a program should do:
Purpose
Input
Processing
Output
