Primitive data types
Any value that you use is of a certain type. In JavaScript, the following are just a few primitive data types:
Number: This includes floating point numbers as well as integers. For example, these values are all numbers-
1
,100
,3
.14
.String: These consist of any number of characters, for example,
a
,one
, andone 2 three
.Boolean: This can be either
true
orfalse
.Undefined: When you try to access a variable that doesn't exist, you get the special value undefined. The same happens when you declare a variable without assigning a value to it yet. JavaScript initializes the variable behind the scenes with the value
undefined
. The undefined data type can only have one value-the special valueundefined
.Null: This is another special data type that can have only one value-the
null
value. It means no value, an empty value, or nothing. The difference with undefined is that if a variable has a null value, it's still defined; it just so happens that its value is nothing. You'll...