Lesson 3: Variables
A variable is a "container" for information you want to store.
A variable's value can change during the script. You can refer to a
variable by name to see its value or to change its value.
Value
A value
in JavaScript is a piece of information that can be a string, number,
Boolean, Null, Object, or a Function as defined in the following table
Value
Types
Type
Description
Example
string
a
series of characters inside quote marks
"JavaScript
is cool"
number
any
numeric value (not inside quotes)
4.55
Boolean
either
true or false
true
Null
Empty,
devoid of any value
null
Object
properties
and methods of an object
see
lesson 5
Function
value
returned by a function
see
lesson 6
Naming Variables
Variable
names are case sensitive
Variables
must begin with a letter or the underscore character
Declaring
a Variable
You
can create a variable with or without the var statement:
var
strname = some value
strname = some value
var= some value
var= a number
Assigning
a Value to a Variable
You
can assign the variable "strname" the value of "groovy"
by:
var
strname = "groovy"
strname = "groovy"
var= "groovy"
var=23.7
