Write within <script> tag
<script type="text/javascipt"> document.write('Hello World'); </script> Semicolons are optional var num1=10 var num2=11 var num3=9;var num4=20; Case sensitivity Javascript is case insensitive
var Num1=10 var NUM2=11 Comments Single line comments
// this is a single line comment Multiline comments
/* This is a multi-line comments that spans multiline */ <noscript> tag The code placed inside noscript will be executed if js is not there
<noscript> Javascript is not available </noscript> Datatypes 3 Primitive data types