Introduction to Programming
History of programming

The first programmer
 The first programmer was a woman –
Ada Lovelace
 Who made the first computer??
 http://www.youtube.com/watch?v=tzUb
xALPcyw
What is programming?
 Programming is breaking a task down into small
steps
Why learn to Program?
 Programming really is fun
 Programmers make lots of money
 Programming is very intellectually rewarding
 Programming makes you feel superior to other people
 Programming gives you complete control over an
innocent, vulnerable machine, which will do your evil
bidding with a loyalty not even your pet dog can rival.
What makes a good programmer?
There are a few traits which might indicate that the person would be a
good programmer:

Logical

Patient

Perceptive

At least moderately intelligent

Enjoys an intellectual challenge

Star Trek fan

Female *
Female *
 Actually, males and females make equally good
programmers.
 It's true that there are currently more male
programmers than female, which is strange given
that one of the first ever programmers (Ada
Lovelace) was female.
How to program?
Here's a quick overview of the process:
 Write a program.
 Compile the program.
 Run the program.
 Debug the program.
 Repeat the whole process until the program is
finished.
Write a program
 Choose a programming language .. There are many
to choose from:
 Java
 C
 C++
 Python
 Create a program is usually called source code, or
just code.
Compile a program

In order to use a program, you usually have to compile it first.

When you write a program, it's not yet in a form that the
computer can use.

Computers actually only understand lots of 1s and 0s in long
streams, known as binary

You can't very well write programs using only vast amounts of 1s
and 0s, so you write it in a more easily-understood form (a
programming language)

Then you convert it to a form that the computer can actually use.

This conversion process is called compiling, or compilation.
Run the program
 Once you have compiled the program into a form
that the computer can use, you want to see if it
works:
 This is called running the program, or sometimes
executing it
Debugging
 It refers to fixing errors and problems with your
program.
 A problem in a program is known as a bug in a
program
Scripting Languages

You've perhaps heard about something called scripting, or maybe you've heard of
languages like JavaScript, AppleScript, Tcl and others (those languages are called
scripting languages).

Scripting is essentially a type of programming

Scripting languages tend to be interpreted rather than compiled, which means that
you don't need to compile them - they're compiled "on the fly”

The fact that scripting languages are interpreted generally makes them slower than
programming languages for intensive operations (like complex calculations)

Scripting languages are often easier to learn than programming languages, but
usually aren't as powerful or flexible

For programming things like applications for personal computers, you'll need to use
a programming language rather than a scripting language
13
Programming Languages:
 Machine Language
 Assembly Language
 High level Language
14
Machine Language
 The fundamental language of the
computer’s processor, also called Low Level
Language.
 All programs are converted into machine
language before they can be executed.
 Consists of combination of 0’s and 1’s that
represent high and low electrical voltage.
15
Assembly Language
 A low level language that is similar to machine
language.
 Uses symbolic operation code to represent the
machine operation code.
16
High Level Language
 Computer (programming) languages that are easier
to learn.
 Uses English like statements.
 Examples are C ++, Visual Basic, Pascal, Fortran and
…....
17
Program Development Cycle:
1. Analyze: Define the problem
2. Design: Plan the solution to the problem
3. Choose the Interface: Select the objects
18
Program Development Cycle:
4. Code: Translate the algorithm into a programming
language.
5. Debug and Test: Locate and remove any errors in the
program.
6. Complete the Documentation: Organize all the
materials that describe the program.
19
Programming Tools:
 Flowchart
 Pseudocode
20
What is a flowchart?
 Logic diagram to describe each step that the
program must perform to arrive at the solution.
 A popular logic tool used for showing an algorithm
in graphics form.
21
Purpose of Flowcharting:
 An aid in developing the logic of a program.
 Verification that all possible conditions have been
considered in a program.
 Provides means of communication with others
about the program.
 A guide in coding the program.
 Documentation for the program.
Chapter 2- Visual Basic
Schneider
Flowchart
Start
The flow chart is made
up of an input, decision
and the alternative
processes or actions.
Temp
(input)
Temp >
25
False
(decision)
True
Turn on A/C
Turn A/C off
(process)
(process)
End
24
Example of Flowchart to show changing
the score
Start
Set Score counter = 0
If Collides with Asteroid
Yes
Change score
Display score
25
What is a Pseudocode?
 A program design technique that uses English
words.
 Has no formal syntactical rules.
26
Example of Pseudocode:
 Determine the average grade of a class:
Declare variable score
Set score variable to 0
If spaceship collides with the asteroid
Get the current score
Increment the score
Output/display new score on the stage
27
Example of Pseudocode:
 Determine the average grade of a class:
Do while there are more data
Get the next Grade
Add the Grade to the Sum
Increment the Counter
Loop
Compute average = Sum / Counter
Display average
Home Learning Task…..See Grid
Useful Resources
 What is computer programming ?
http://www.youtube.com/watch?v=OWsyrnOBsJs