Number—this includes floating point numbers as well as integers, for example 1, 100, 3.14.
String—any number of characters, for example "a", "one", "one 2 three".
Boolean—can be either
Undefined—when you try to access a variable that doesn't exist, you get the special value
Null—this is another special data type that can have only one value, the
nullvalue. It means no value, an empty value, nothing. The difference with
undefinedis that if a variable has a value
null, it is still defined, it only happens that its value is nothing. You'll see some examples shortly.
Any value that doesn't belong to one of the five primitive types listed above is an object. Even
null is considered an...