Velocity Reviews

Velocity Reviews (http://www.velocityreviews.com/forums/index.php)
-   Javascript (http://www.velocityreviews.com/forums/f68-javascript.html)
-   -   im a total NEWB i need a little help understanding this script..specific instances are noted. (http://www.velocityreviews.com/forums/t870826-im-a-total-newb-i-need-a-little-help-understanding-this-script-specific-instances-are-noted.html)

nightsaber 07-15-2003 02:00 PM

im a total NEWB i need a little help understanding this script..specific instances are noted.
 
<script language="JavaScript">
<!-- hide me

var the_number = prompt("how many words (3-5 is good)?", "4");
var the_string = "";
var a_word;

for (loop = 0; loop < the_number; loop++)
{
line_number = loop + 1;
a_word = prompt("what's word " + line_number + "?","");
the_string = "word " + line_number + ": " + a_word + "<br>" +
the_string;
}
var new_window =
window.open("reverse.html","reverse","height=400,w idth=400");
new_window.document.writeln("<h1>In reverse</h1>");
new_window.document.writeln(the_string);

// show me -->
</script>
ok heres what i DONT get and it kinda screws upo the whole thing for
me.
>for (loop = 0; loop < the_number; loop++) ok loop++ means loop = loop +1 so loop is now 1 <0+1=1>
>{
> line_number = loop + 1; at this point it ADDS 1 to loop which is as i said 1 making "line_number" = 2 <1+1>

yet thats NOT how it works. it puts the value as 1. take out the +1
part and it makes the line number 0 ...i just dont get this at all. i
started on this java tutorial thing today at 7am..... its now 2 45 am
I understand the majority of it up to here....
of course
>the_string = "word " + line_number + ": " + a_word + "<br>" + the_string; kinda throws me it seems like its saying the _string = "word 1 : apple"+"word 1 : apple"

but i suppose im being to literal. i am guessing this adds the
afformentioned value to itself so the _string DOESNT= "word 1 :
apple"+"word 1 : apple"it just = "word 1 : apple" and whatever the
next word is will be added to that so it will be the_string="word 2
:orange, word 1 :apple"
any help is appreciated. i like to understand not only HOW but WHY?!
cause i see what it does i just dont know WHY and that bugs the heck
outta me.



Michael Stemper 07-17-2003 04:46 PM

Re: im a total NEWB i need a little help understanding this script..specific instances are noted.
 
In article <0728hvkhpr0e3en2frcitlppkp6bstkd3g@4ax.com>, nightsaber <nightsaber@hotmail.com> writes:

>for (loop = 0; loop < the_number; loop++)
>{
> line_number = loop + 1;
> a_word = prompt("what's word " + line_number + "?","");
> the_string = "word " + line_number + ": " + a_word + "<br>" + the_string;
>}


>ok heres what i DONT get and it kinda screws upo the whole thing for
>me.
>>for (loop = 0; loop < the_number; loop++) ok loop++ means loop = loop +1 so loop is now 1 <0+1=1>


This is what's called a "for loop". The three things in the for statement
are:
initializtion: loop = 0;
test: loop < the_number;
increment: loop++;

The way that a for loop works is:
1. Execute the initialization:
loop = 0;
2. Execute the contents of the loop
{
line_number = loop + 1;
a_word = prompt("what's word " + line_number + "?","");
the_string = "word " + line_number + ": " + a_word + "<br>" + the_string;
}
(Note that, at this point, the value of "loop" is zero.)
3. Execute the increment:
loop++;
(Only at this point does "loop" get set to one.)
4. Execute the test:
loop < the_number;
If the test is satisfied (IOW, if "loop" is less than "the_number"),
you go back to step 2, and the contents of the loop are again
executed.

>> line_number = loop + 1; at this point it ADDS 1 to loop which is as i said 1 making "line_number" = 2 <1+1>


But, that addition doesn't happen until after the contents of the loop
have been executed.

--
Michael F. Stemper
#include <Standard_Disclaimer>
Give a man a fish, and you feed him for a day. Teach him how to fish,
and you can sell him equipment.



All times are GMT. The time now is 06:03 AM.

Powered by vBulletin®. Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO ©2010, Crawlability, Inc.