1. Introduction to programming
ICS2O
Mr. Lane & Mr. Findlay

2. agenda We will learn What is a Program What is a programming language
The difference between source code and machine code
The difference between an interpreter and a compiler
Working with Java

3. Which Specimen is a Program?
Specimen 1: How to be a Glutton
Specimen 2: Binary
Buy cookie dough
Lay out cookie dough on tray in 5 cm diameter circular goodness
Preheat oven to 425 degrees Fahrenheit
Place cookie tray with cookies in oven for 15 minutes
Remove tray and proceed with gluttony

4. A Program Is…
A plan that lays out a sequence of actions to achieve a goal

5. Why Was “How to be a Glutton” More Like a Program than the “Binary”?
It was recipe for how to be a glutton
It gave step-by-step actions starting from the beginning to the end
After finishing the program you achieve the desired goal: being a glutton
The binary was just a bunch of numbers, not a real program. We had no idea if it represented anything or not

6. Let’s Try it out! Objective: What do we notice from this activity?
Try to come up with the steps to Instruct an alien to put on a jacket when they can only understand basic things like colour, material type, Up and Down, etc.
What do we notice from this activity?
Clearly stating the steps to achieve a task is not easy
We cannot make any assumptions

7. What is a Programming Language?
An artificial language similar to English designed to give instructions to a computer
This language is made up of special words called Keywords
We refer to this collection of keywords as a dictionary, if you try to use a word not in the dictionary you will get an error
The use of this language must follow a set of rules, in English we call these rules grammar. IN programming we call this set of rules Syntax
Syntax is the set of rules and formatting that govern programming instructions to ensure their validity so they can be recognized by the computer
Examples of Programming Languages
Turing, C, C#, C++, Java, JavaScript, Basic, HTML, Python, Action Script, etc.

8. Source Code What is source code?
This is the code that you write
It usually looks like English words
Example: System.out.println(“Hello World!”);
Source code is meant to be read by people
Easy to understand for computer scientists, and sometimes understandable to non-techies
Often times we refer to it simply as code.
This is because a code refers to something only readable by the intended audience. Program code is intended to be read by other programmers, not the average person. Therefore it looks like code to them.

9. Machine code What is the problem with source code?
Machines cannot understand source code
Imagine a new student shows up in class tomorrow that speaks Russian. The teacher does not. How will the teacher communicate with the student?
A translator, someone to convert my English into Russian and vise versa
We need something similar for our programs, a translator
In programming we call this translator a Compiler
Machine code is simply a collection of 1’s and 0’s called binary, this is what a computer can understand
Source Code
 Compiler
 Machine Code

10. Other Translators
A compiler goes through all of the machine code and translates it into machine code all at once
There is another type of translator out there called an Interpreter
An interpreter works similarly to a compiler but has one major difference, rather than compile all code at once, it compiles it one line at a time.
This allows for a faster initial start and easy bug fixing.
However it is actually slower as it is executing because it needs to both convert and execute the code
Most scripting languages such as HTML, PHP and JavaScript are interpreted languages whereas languages such as C, C#, C++ and Swift are compiled languages. Java is both compiled AND interpreted.

11. Working with Java
When writing our programs we use a tool called an Integrated Development Environment (IDE).
This tools is very powerful, it allows us to edit, compile, test and fix our code all in a single piece of software
The number one IDE for Java is Eclipse, the IDE we will use in our class.
Other handy features IDE’s offer are text highlighting, text- completion (called intellisense) and a collection of debugging (code fixing) tools.
The next few quests will help you setup and familiarize yourself with the Eclipse IDE for later use in the course.