Basic of Programming Language

Skill Area 304.1Materials Prepared by Dhimas Ruswanto, BMm

Lecture Overview

• Computer System• Computer Program• Programming

Language• Programmer• Translators

Computer System

Input Devices

Processing(CPU/Memory) Output

Devices

Storage Devices

Computer System

• Also called CPU, processor or microprocessor

• “Brains” of the computer• Performs all computer

operations

CPU

• Where all the input data and results storedoRandom Access Memory (RAM)oRead Only Memory (ROM)

Main Memory

• RAM is volatile = data are lost when computer is turned off

• Read current info and also write new info• Very important in determining capabilities of

the computer system• Stores work when they are in use.

o Word Documento Spreadsheeto Power Point

RAM

• ROM is non-volatile = permanent and are not affected where computer is turned lost

• Can read info Stored in ROM• Can not write new info into ROM• Used for “internal workings” of computer

– Boot Software

ROM

Computer Program

Computer Program• A program or computer

program is a set of instructions that tells a computer how to perform a particular task.

• Programs are developed using programming language.

• Computer programming is the art of developing computer programs.

• Programming is rather like a recipe; describe the ingredients (the data) and the sequence of steps (the process)

Computer Program (cont’d)• A program is developed to

help the activity of humans easier

• Examples:– Banks– Communication– Business– Medical Science– Education– Travel and Ticketing– Daily Life– etc

Programming Language• A programming language is a vocabulary

and set of grammatical rules for instructing a computer to perform specific tasks

• Programming language provides a set of rules to develop a program.

• A Programmer is a person who writes a computer program.

• The job of programmer is to convert a solution to a problem into set of instructions understood by a computer.

• The programmer should test the program to see whether it is working.

• Corrective actions should be taken if not working properly.

Programmer

When we want to write a program to solve a problem,• the hardest is to know how to start,• we also need to work out the steps

to take for reaching the solution,

• we also need to be sure that the program works

without errors, according to the specifications.

Programmer (cont’d)

Why Programming?• Three good reasons for learning

programming:– Programming helps you understand

computers.– Writing a few simple programs increases

your confidence level.– Learning programming lets you find out

quickly whether you like programming and whether you have the analytical turn of mind programmers need.

Types of Programming Language

• Three types of Programming Language–Machine Language–Assembly Language–High-Level Language

Machine Language• The lowest and most

elementary level of Programming Language.

• 1st type of PL to be developed.• Represented inside the

computer by a String of binary digits (bits) 0 and 1.

• The symbol 0 stands for the absence of Electric Pulse and 1 for the presence of an electric pulse

Why Machine Language?• Their order tells the computer what to

do.• All other kinds of software need to be

translated into machine code before they can be used.

Assembly Language• Symbolic instruction what humans

can understand• Form of alphanumeric symbols known

as mnemonic codes.• Can have maximum up to 5 letter

combination• E.g.

– ADD for addition– SUB for subtraction

Why Assembly Language?

• Maps directly into machine language

• Designed for a family of microprocessorsMOV AX, BXADD AX, 5AINC BXJMP 100

01010011110110101101101001110101001010101010

Compile

High-Level Language

• High-Level language is basically symbolic languages that use English words and/or mathematical symbols rather than mnemonic codes.

• Each instruction in the high-level language is translated into many machine language instructions.

Purpose of High-Level Language• To enable people (programmer)

to write program easily and in their own native language environment (English).

• Examples:– C, C++, Java, VB, HTML

Types of High-Level Language

• Languages have been developed for general purpose and specific purpose

• Types of High-Level Languages:– Algebraic Formula-Type Processing– Business Data Processing– String and List Processing– Object Oriented Programming

Language (OOP)– Visual Programming Language

Translators

Translators• Types of Programming Language

Translators:– Assembler– Interpreter– Compiler

Assembler

• To convert the assembly language into machine code.

• Translate mnemonic operation codes to their machine language equivalents.

Interpreter• A computer program that executes

instructions written in a programming language and do not produces the executable file.

• Interpreter:o Checks the keywords of a programo Taking one instruction at a time and convert it into machine

language before taking upon the next instruction.• Examples of interpreter based language:

o PHP, JavaScript, BASIC

Complier

• A program that changes source code (high-level language) to object code which that can be executed by a machine.

• Compiler:o Checks syntax of programo Checks at a time all the program

• Primary reason for compiling source code is to create an executable program

• Examples of compiler based language:• C, C++, JAVA

Executables

• Executables: Files that actually do something by carrying out a set of instructions.

• E.g., .exe files in Windows • Once the executable is there, it can be

called by the user to process the given inputs to a program and produce the desired outputs.

SUMMARY• Computer System (CPU, Main Memory, Keyboard, Mouse, etc)• Computer Program

• a set of instructions that tells a computer how to perform a particular task.

• Programming Language• a vocabulary and set of grammatical rules for instructing a

computer to perform specific tasks• Programmer - a person who writes a computer program• Types of PL

• Machine Language• Assembly Language• High-Level Language

• Translators• Interpreter• Assembler• Compiler