• Javascript Basic Datatypes

    • Basic Datatypes
      • number
      • string
      • boolean
      • undefined
      • null

    1. number

    • For numbers (e.g., int, long, float, double), there is only one datatype, number, in Javascript.

    2. string

    • Immutable
    • Sequencing

    • string conversion
      • When you use a number-like string as an operand in an arithmetic operation, the string is converted to a number behind the scenes.
      • This works for all operations except addition

    3. boolean

    • The boolean variable represents two values: “true” or “false”.
    • If the boolean variable has no initial value, or if the assigned value is one of the followings, it is set to false.
      • 0
      • -0
      • null
      • “”
      • false
      • undefined
      • NaN
    • For any other value, it is set to true (even with the string “false”)!

    4. undefined

    • type of undefined is undefined.

    5. null

    • type of null is not null, but object.
    • null will be evaluated to 0 (zero), if it is evaluated with other number.

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