Used to track values as they change over the course of a program.

A symbol or set of symbols that can change value over time.

• Name

• Value

• Type

"String"

"Hello World!"

Number

42

Boolean

true

text = "Hello World"
count = 12
ugly = false

'Character'

'H'

Double

42.215

firstInitial = 'M'
taxRate = 0.75

What can you do with numbers? Maths!

100 / 10 - 6

2 * (10 + 6)

a = 12

b = a * 3

Special Numbers

NaN

Infinity

Text inside of quotes

"Welcome to monkey island"
'The Gorillas raped that girl'

Your supposed to use single quotes for strings though...

'Thats what "she" said'
"Your 'elephant' is huge"

Quotes inside of quotes

'Winter is \'comming\''
'Lorem ipsum dolor sit amet,\nconsectetur adipiscing elit.'

Trailing backslash before quotes prevents excapes

Special characters inside of strings

\n creates a new line

Addings strings togeather (concatination)

'Hello' + ' ' + 'World'

a = 'Hello'
b = ' '
c = 'world!'

a + b + c

Single Line

//this won't be seen by program

Comment Block

/* Comment Blocks Need Closing Tags */

firstInitial = 'M' //for mathew

/*
 This Next Part calculates Taxes
*/

taxRate = 0.75 

Go to the next line

;

firstInitial = 'M'
secondlineVariable = 10;

{
  indentAThing = 11
  intentSecondThing = 12;
}

Code Block

{        

  // some code here ...      

}

firstInitial = 'M'secondlineVariable = 10;
{indentAThing = 11intentSecondThing = 12;}

firstInitial = 'M';
secondlineVariable = 10;

{
  indentAThing = 11;
  intentSecondThing = 12;
}

firstInitial = 'M';
secondlineVariable = 10;
{indentAThing = 11;
intentSecondThing = 12;}

Minus

-

Plus

+

a = 10 - b
b = c + 7

Double Minus

--

Double Plus

++

a = 10
a++
a == 11 //true

a = 10
a--
a == 9 //true

Multiplication

*

a = 10 * b

Division

/

a = 10/5
a == 2

Equals

=

a = 10
b = c + 1

Double Equals

==

Checking Equality

a = 10
a++
a == 11 //true

a = 10
a--
a != 10 //true

'Assignment'

Not Equals

!=

Checking Inequality

a = 10
a++
a != 11 //false

a = 10
a--
a == 9 //true

Triple Equals

===

a = 10
a === "10" //false

a = 5
a === 5 //true

"Hello" !== "hello" //true
"true" !== false //true

a = "10"
a !== 10 //true

Matches Type

tax = "false"
tax === true //false

tax = 0
tax == false //true

Triple Not Equals

!==