JavaScript Language Characteristics

Case Sensitivity:

Consider the following example

< img src="plus.gif" alt="Increment x" onclick="x=x+1">

< img src="plus.gif" alt="Increment x" onclick="X=X+1">

both not equivalentbecause first modifies the variable "x" where as second modifies the variable"X".Because java script is case-sensitiv.
The onclick HTML attribute is not case-sensitive and so may be written onClick, ONCLICK, or even oNcLiCk. However, because the value to which it is set contains JavaScript, its value is case-sensitive.


White Space:

Any sequence of excessive whitespace characters is ignored by JavaScript.

Consider the following:

s = typeof x;
s = typeofx;

The first statement invokes the typeof operator on a variable x and places the result in s. The second copies the value of a variable called typeofx into s. One space changes the entire meaning of the statement.

Statements :


consider this example:
x = y + 1 ;
This will add y with 1 & value is stored in x


semicolons indicates the end of the javascript statement,So we can write multiple satements in one line like this
x = x + 1; y = y + 1;z = z + 1;

Although statements are generally followed by semicolons, they can be omitted if your statements are separated by a line break

x = x + 1
y = y - 1

is treated as

x = x + 1;
y = y - 1;

But while writing return we have to be care full...if we write it like this ...
return

x

then it will be treated as
return;

x;

insted we should write it like this
return x;