DEV Community

Cover image for Basic JavaScript - Comments, Data Types, Variables

Basic JavaScript - Comments, Data Types, Variables

Amritanshu Dev Rawat
New Gen Developer
・1 min read


  2. Data Types
  3. Variables


  • Comments are lines of code that JavaScript will ignore. Comments are used to leave some notes to your future self and to other people who will later open your code.
  • There are two ways to type comments in JS.
  • // is used for inline comment.
  • /**/ is used for multi line comment.
  • /** */ is used for documentation image

Data Types

  • Data is anything that is meaningful to the computer. Like we have videos, texts, songs, etc. In general we can say a text a data type, we can't store a video in a text file or a text in a video file, they are different data types.
  • JavaScript provides eight different data types which are undefined, null, boolean, string, symbol, bigint, number, and object.
  • number - 1,2,3...
  • strings - "abcd.."
  • boolean - true, false
  • etc



  • Variables are similar to the x and y variables you use in mathematics but in computer we use variable to point to some value, means they are just a simple name referring at some value.
  • In JavaScript we can define variable in different ways.

This is just a basic intro from my side, you can learn more from:

Discussion (0)