Comments
javaScript Comments are use to make our code more readale and easy to understand. Comments are not display on the browser,they are only Define our souce code in a different sections.
Single Line Comments
We can write single line comments in javaScript with //.
If you keep any code after // that code will not display on the browser.
Example:
// change myHeading
 document.getElementById("heading").innerHTML="CodesFamily";
 //Change heading Text Color
 document.getElementById("heading").style.color="red";
Example:
 
var a=10; 
 var b=20;  
 varc=a+b 
Multi Line Comments
In javaScript Multiline Comments starts with /* and end with */ always.
If you keep your code between /* code */ that code will not be execyued.
Example:
/* This is my code and I want to 
change my heading and it's c color.*/
 document.getElementById("heading").innerHTML="CodesFamily";
 document.getElementById("heading").style.color="red";