1. Chapter 10 Programming Fundamentals with JavaScript

2. In this lecture, you will learn:
the differences between programming languages and scripting languages
programming concepts and constructs: syntax, data types, variables, statements, assignment statements, operators, constants, keywords, expressions

3. Coding Writing code Run, running, execution Compiling, compilation
means entering the code
is part of the process of creating the computer program
Run, running, execution
refers to the process by which the computer carries out the instructions in a computer program
Compiling, compilation
refers to the process of assembling code into a format suitable for the computer to execute the instructions

4. IDE stands for: Integrated Development Environment refers to:
the software in which you are developing an application
for example, Adobe Animate, Microsoft Visual Studio

5. Programming Languages
Multimedia authoring scripting languages, such as JavaScript and Animate Actionscript are often the highest level.
high level Programming languages that look more like human language.
Easy for human to read and write, but require more "translation" behind the scenes to be understandable to the computer.
e.g. C++, C#, Java, FORTRAN
Assembly language
low level
lowest level:
Machine language: a programming language that communicates with a computer through 0's and 1's

6. Scripting Languages Examples: Javascript and Animate ActionScript
Very-high-level programming languages
Advantage: easier for non-programmer to learn because the syntax and keywords are close to human languages
Disadvantages:
Not as full-fledged as programming languages such as C++, Java, and FORTRAN
Don't have the features to let the programmer to control low level details, such as memory allocation

7. JavaScript Syntax
prescribes the ways in which statements must be written in order for them to be understood by the computer
like the rules of grammar and punctuation in human languages, but these rules must be followed precisely in computer programming
for examples, for JavaScript:
case sensitive
each statement ends with a semi-colon(;)
the naming of variables and functions has to start with a letter , _ or $

8. Basic Programming Constructs
syntax
variables
statements
assignment statements
keywords
operators
expressions
procedures
functions
arguments
control structures
conditions
comments
arrays
loops
In this Powerpoint

9. Variables
Purpose: to store values that can be updated and retrieved at runtime
Data is stored in memory as bits.
Variable lets you refer, by name, to the data's memory location stored.
has 3 Properties:
Name: Code refers to memory location by name
Value:The actual information stored at the location
Type: The particular type of data (data type) Examples: integer, floating point, string

10. Loose vs. Strict Data Typing
When a programming language requires that you explicitly declare the data type of a variable when the variable is first created
Loose data typing
When a programming language does not have such data typing requirement.
JavaScript is loosely typed language

11. Variable Naming
can contain a number, a letter, underscore (_), or dollar sign ($)
cannot begin with a number
in this course, variables always begin with a letter
must not contain spaces
cannot be a keyword
score and Score are different
number and nuMBer are different

12. Variable Naming Which are valid variable names? myScore my_score
myScore -- valid
my_score -- valid
my score -- invalid because of the space
my-score -- invalid because of the dash (-), which is the substraction operator
my4score -- valid
4score -- invalid because it starts with a number

13. Assigning a Value to a Variable
Means giving a value to a variable
The statement that assigns a value to a variable is called an assignment statement.
General Syntax:
variableName = value or expression;
Examples:
score = 10;
letterGrade = "A";
sum = a + b;

14. Statements Statements are instructions that can be executed
A statement ends with a semi-colon (;) when there are more than one statements on the same line
Purposes: For examples,
to give values to variables (assignment statements)
to cause things to happen only under certain conditions (e.g. if-statements)
to cause instructions to repeat (used in loops)

15. Operators
symbols that cause a new value to be calculated from one or more other values
Examples:
arithmetic: +, -, *, /, % give new calculated values
comparison operators: >, >=, <, <=, ==, != give a value of true or false
logical operators: &&, ||,! give a value of true or false

16. Assignment Operators =, +=, -=, *=, /=, %=
score += 3;
score = score + 3;
score -= 3;
score = score – 3;
score *= 3;
score = score * 3;
score /= 3;
score = score / 3;
score %= 3;
score = score % 3;

17. Assignment Operators =, +=, -=, *=, /=, %=
score = 10; score += 5; What is the value for score after these two statements?
Answer: 15

18. Assignment Operators =, +=, -=, *=, /=, %=
score = 10; score *= 2; What is the value for score after these two statements?
Answer: 20

19. Keywords
Reserved words that have a special meaning in a programming language.
 You are not allowed to use these words for any other purpose, such as variable or function names.
Examples:
var if
for
function
true
false

20. How a Program Runs
A program is written as a sequence of statements as instructions.
The program executes the instructions sequentially--one instruction after the other, in the order in which they appear in the code.
Use control structures to make nonsequential execution of the instructions.

21. Types of Control Structures
Loop
A set of statements is executed repeatedly until a certain condition is reached
Will be covered in Chapter 11
Conditional
A set of statements is executed only if some conditions are met
if statements and switch statements

22. if Statements if
if...else
if...else if
Nested if statements

23. if General Syntax: if (logical expression(s)) { statement(s) }
The statements grouped within the curly braces are called the block statements.

24. if
If there is only one statement to be executed, the curly braces are optional.
Examples:
if (score > 60)
grade = "pass";
The statement may be on a single line:
if (score > 60) grade = "pass";

25. if...else
General Syntax: if (logical expression(s)) { statement(s) } else

26. if...else
Example: if (score > 60) { grade = "pass"; } else grade = "fail";

27. if...else if
General Syntax: if (logical expression(s)) { statement(s) } else if (logical expression(s)) ... else

28. if...else if
Example: if (score > 90) { grade = "A"; } else if (score > 80) grade = "B"; else if (score > 70) grade = "C"; else if (score > 60) grade = "D"; else grade = "F";

29. if...else if The conditions are checked one at a time sequentially.
Once a condition is found to be true, the statement(s) for that condition will be executed and the rest of the conditions in the if else if statements group will not be checked.

30. if...else if Suppose score = 85.
Example: if (score > 90) { grade = "A"; } else if (score > 80) grade = "B"; else if (score > 70) grade = "C"; else if (score > 60) grade = "D"; else grade = "F";

31. if...else if Suppose score = 85. First check: (score > 90).
(85 > 90) is false!
Example: if (score > 90) { grade = "A"; } else if (score > 80) grade = "B"; else if (score > 70) grade = "C"; else if (score > 60) grade = "D"; else grade = "F";

32. Logical Operators
&& AND
|| OR
! NOT

33. Logical AND: &&
logicalExpression1 && logicalExpression2 true : only when both logicalExpression1 and logicalExpression2 are true false : when either logicalExpression1 or logicalExpression2 is false

34. Logical OR: ||
logicalExpression1 || logicalExpression2 true : when either logicalExpression1 or logicalExpression2 is true false : only when both logicalExpression1 and logicalExpression2 is false

35. Logical NOT: !
!logicalExpression1 true : when logicalExpression1 is false false : when logicalExpression1 is true

36. Examples Example 1 Example 2
if (age < 40 && weight < 150) { group = 2; } else group = 3;
if (age < 40 || weight < 150) { group = 2; } else group = 3;
Example 1: group = 2
Example 2: group = 2
Which statement will be executed in these examples when age = 38 and weight = 145?

37. Examples Example 1 Example 2
if (age < 40 && weight < 150) { group = 2; } else group = 3;
if (age < 40 || weight < 150) { group = 2; } else group = 3;
Example 1: group = 3
Example 2: group = 2
Which statement will be executed in these examples when age = 38 and weight = 157?

38. Examples Example 1 Example 2
if (age < 40 && weight < 150) { group = 2; } else group = 3;
if (age < 40 || weight < 150) { group = 2; } else group = 3;
Example 1: group = 3
Example 2: group = 2
Which statement will be executed in these examples when age = 46 and weight = 145?

39. Examples Example 1 Example 2
if (age < 40 && weight < 150) { group = 2; } else group = 3;
if (age < 40 || weight < 150) { group = 2; } else group = 3;
Example 1: group = 3
Example 2: group = 3
Which statement will be executed in these examples when age = 46 and weight = 157?