Primitive data types
Any value that you use is of a certain type. In JavaScript, there 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"
, and"one 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 valueundefined
. The undefined data type can only have one value – the special valueundefined
. - Null: This is another special data ...
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