Primitive data types

Any value that you use is of a certain type. In JavaScript, there are just a few primitive data types:

  1. Number: This includes floating point numbers as well as integers. For example, these values are all numbers: 1, 100, 3.14.
  2. String: These consist of any number of characters, for example "a", "one", and "one 2 three".
  3. Boolean: This can be either true or false.
  4. 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 value undefined.
  5. Null: This is another special data ...

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