ITEC 320

Procedural ProgrammingDr. Ray

Lecture 1

Introduction

Outline

• Welcome• Intro to the course• Ada – first steps

Introduction

Syllabus

• R Lectures / Interactive demonstrations• Office Hours 2:00-3:00 PM MTWF– Saturday 7:00-8:00PM or Sun. 3:00-4:00

• Website– www.radford.edu/aaray => ITEC 320

• D2L for submission• Projects• Homework• Exams

Introduction

Introduction

• On a scale of 1 to 10, how interested are you in learning a different language?

• How many lines of code did you write for the largest program you’ve worked on?

• What do you want to learn in this course?

• Share with your neighbor• Introduce yourselves and answers to

the class

Introduction

Languages

• What advantages are there to learning a new computer language?

• What are the some of the reasons for learning a new language?

• Why is this important?– Objective C example

Introduction

1970s

• The era of…• Multiple languages used at the

DOD…• What are some of the problems with

using multiple languages?• What happens when you use multiple

languages for one project?

Introduction

Solution

• Design competition

Introduction

Result

• Procedural / OO mixed language• Multi-threaded / generics• Reliability and maintenance• Readability over writability

$line =~ /.{28}(\d\d)-(\d\d)-(\d\d).{8}(.+)$/

Introduction

Differences

Java

Ada

public class HelloWorld{

public static void main(String[] args){

int x;x=3;System.out.println(x);

}}

with ada.text_io;with ada.integer_text_io;procedure hello1 is x: Integer;begin x := 3; ada.text_io.put_line("Hello World"); ada.integer_text_io.put(x);end hello1;

Introduction

First impressions

• What are your thoughts on what you just saw?

with ada.text_io;with ada.integer_text_io;procedure hello1 is x: Integer;begin x := 3; ada.text_io.put_line("Hello World"); ada.integer_text_io.put(x);end hello1;

Introduction

How to make it work

• Write / Compile / Execute cycle• Editors– vi filename.adb

• Compiler– gnatmake filename

• Execution– filename or ./filename (Mac)

Introduction

Types

• Why is it important to know what type of variable it is that you are using?

• What are the different types of variables you are familiar with?

Introduction

Information

• Largest and smallest numbers possible• Integer add

– ‘first;– ‘last;– ‘range;

• Character– ‘val(65);– ‘pos(‘A’);

• Boolean– Boolean’val(0);– Boolean’pos(true);

Introduction

Extra types

• Natural– 0 to Integer’Last --Biggest integer

• Positive– 1 to Integer’Last

• Chance– 0.0 to 1.0 --Constrained float

Introduction

More types

• Character (8 bit)• Wide_Character (16 bit)• Wide_Wide_Character (32 bit)• Strings– Arrays of characters– Fixed length– 3 types (more later)

Introduction

Conversion

• Anything to String

• String to Integer

• Character conversions

intVar’imgintVar’image

Integer’val(“12”);Integer’value(“123”);

Character’val(65);Character’pos(‘A’);

Introduction

Output

• Convert non-strings to strings– Combine strings with the &

• Output and stay on same line– put( );

• Output and goto next line– put_line( );

• Enter key– new_line;

Introduction

Formatting Output

• width–minimum width

• fore–Minimum number of places before

decimal

• aft– Number of places after decimal

• exp–Minimum number of places for the

exponent

put(var, width=>2);

Introduction

Type checking

• Both sides of assignments must match

• Operands of arithmetic operators must match

• Must do it all manually– In Java, int’s will be converted to floats

• Extends to output– System.out.println how we will miss thee– ada.integer_text_io.put(3);– ada.text_io.put(“Lots of typing”);

Introduction

Summary

• Short day• History of ADA• Basics of the language• Introductory comparison of the

languages