JavaScript data-types

JavaScript is a versatile language that's used in programming everything from web pages to servers and desktop applications. We will use this interactive tutorial as a reference in our journey.

JavaScript is different from the other languages we've seen here (C++, C#, Java), in that it doesn't have a compiler. The code is interpreted while running it.

This brings us to a distinction in data-types as well. JavaScript doesn't fix the type of its variables. For example, this is a valid sequence for the interpreter:

var x;           // x is undefined to start with
x = 15;          // After this assignment, x is a Number
x = "Phil";      // Here x becomes a String

Many other fun things can happen with JavaScript data, as you can see here.

What could be the use of such flexibility? Tell us what you feel below.
Hint: Think of real-life arrays - like array of vehicles, array of chat messages, etc.

Once you are done, let's step into functions, the core of JavaScript.

Comments

  1. RaPa Learning15 April 2019 at 16:52

    An array of vehicles is heterogeneous - each element can be a different vehicle. But an array normally holds many elements of one type. Can we have heterogeneous arrays?

    ReplyDelete
  2. geekr12 May 2019 at 23:44

    Yes we can have heterogeneous arrays in javascript. since we can store different data type elements in an array like string , number, boolean can be store in a single array.

    ReplyDelete
    Replies
    1. RaPa Learning26 May 2019 at 09:46

      Definitely! But wouldn't that be hard to read? How will a reader of the data know if an element is a string, number or boolean?
      Or do they need to know?...

      Delete
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