JavaScript Programming

JavaScript is Case Sensitive

A function named "myfunction" is not the same as "myFunction". Therefore watch your capitalization when you create or call variables, objects and functions. 

Symbols

Open symbols, like  ( { [ " ', must have a matching closing symbol, like  ' " ] } ).

White Space

JavaScript ignores extra spaces. You can add white space to your script to make it more readable. These lines are equivalent:

name="Hege"
name = "Hege"

Break up a Code Line

You can break up a code line within a text string with a backslash. The example below will be displayed properly:

document.write("Hello \
World!")

Note: You can not break up a code line like this:

document.write \
("Hello World!")

The example above will cause an error.

Insert Special Characters

You can insert special characters (like " ' ; &) with the backslash:

document.write ("You \& I sing \"Happy Birthday\".") 

The example above will produce this output:

You & I sing "Happy Birthday".

Comments

You can add a comment to your JavaScript code starting the comment with two slashes "//":

sum=a + b  //calculating the sum

You can also add a comment to the JavaScript code, starting the comment with "/*" and ending it with "*/"

sum=a + b  /*calculating the sum*/

Using "/*" and "*/" is the only way to create a multi-line comment:

/* This is a comment
block. It contains
several lines*/