Programming languages have come a long way since the early days
on what it is meant to do:
- If the result is required at a particular location on a page,
the section is placed where the result is wanted
- If the section contains code which other parts of the document
make use of (functions
for example), the code should be placed at the begining of
the document (between the <HEAD> </HEAD> tags
is a good place). Trying to make calls to sections which appear
further down the document can fail, because those sections may
not have been read yet.
A programming language allows symbols to be manipulated (expressions)
and evaluated (operators).
The object hierarchy lists objects, such as a window or a document.
There also fundamental things a programming language must deal with,
such as numbers, text and true/false scenarios. These symbols are
essential if useful programs are to be developed.
before trying to understand the language statements. This is because
the language needs expressions to perform its tasks.
The followinfg link
A programming language allows a sequence of statements (commands)
to be defined.
A programming language allows a designer (programmer to non programmers)
to lay out a set of steps, or rules, needed to do something. At
its simplest level it can be just one command, but not much can
be achieved at this level.
This is a simple example, which displays today's date:
If we use two commands, the first command is executed then
the second one. This happens faster than the eye can see. It is
important to understand that an ordered sequence of commands we
write is executed in the order we designed. We can control a sequence
of events which is repeated by anyone who happens to run the program,
This example has two commands to display the date this page was
last modified, and today's date:
document.write(" ", Date())
many statements are put on the same line, they must be seperated
by a semi-colon ;
is not the same as a lower case character: www is not the same
as wWw or WWW.
The following link