Velocity Reviews > my function needs a for loop.

# my function needs a for loop.

Abby Lee
Guest
Posts: n/a

 09-03-2004
My function works but there has got to be a way to make a for loop to
handle this...but I can't get a for loop to work. You can tell, I'm
not very good at this...help.

"myvalue" is the number of miles the person enters
"myitem" is the row...there are seven rows where they can list
expenses.
"myvalue" * .375 = amount to be reimbursed
All the rows are added and placed into the total.

function autoReimb(myvalue,myitem){
var nrow = "autoReimb" + myitem;
if(isPositiveInteger(myvalue.value)){
var amount = myvalue.value * .375;
formatedamt = format(amount)
eval("document.forms[0]." + nrow + ".value = formatedamt");
if(isPositiveInteger(document.forms[0].miles1.value))
var reimb1 = document.forms[0].autoReimb1.value;
else var reimb1 = 0;
if(isPositiveInteger(document.forms[0].miles2.value))
var reimb2 = document.forms[0].autoReimb2.value;
else var reimb2 = 0;
if(isPositiveInteger(document.forms[0].miles3.value))
var reimb3 = document.forms[0].autoReimb3.value;
else var reimb3 = 0;
if(isPositiveInteger(document.forms[0].miles4.value))
var reimb4 = document.forms[0].autoReimb4.value;
else var reimb4 = 0;
if(isPositiveInteger(document.forms[0].miles5.value))
var reimb5 = document.forms[0].autoReimb5.value;
else var reimb5 = 0;
if(isPositiveInteger(document.forms[0].miles6.value))
var reimb6 = document.forms[0].autoReimb6.value;
else var reimb6 = 0;
if(isPositiveInteger(document.forms[0].miles5.value))
var reimb7 = document.forms[0].autoReimb7.value;
else var reimb7 = 0;

var totalauto = (reimb1 * 1) + (reimb2 * 1) + (reimb3 * 1) + (reimb4
* 1) + (reimb5 * 1) + (reimb6 * 1) + (reimb7 * 1);
document.forms[0].autotot.value = format(totalauto);
}
else eval("document.forms[0]." + nrow + ".value = ''");
} //End Function

McKirahan
Guest
Posts: n/a

 09-03-2004
"Abby Lee" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> My function works but there has got to be a way to make a for loop to
> handle this...but I can't get a for loop to work. You can tell, I'm
> not very good at this...help.
>
> "myvalue" is the number of miles the person enters
> "myitem" is the row...there are seven rows where they can list
> expenses.
> "myvalue" * .375 = amount to be reimbursed
> All the rows are added and placed into the total.
>
>
> function autoReimb(myvalue,myitem){
> var nrow = "autoReimb" + myitem;
> if(isPositiveInteger(myvalue.value)){
> var amount = myvalue.value * .375;
> formatedamt = format(amount)
> eval("document.forms[0]." + nrow + ".value = formatedamt");
> if(isPositiveInteger(document.forms[0].miles1.value))
> var reimb1 = document.forms[0].autoReimb1.value;
> else var reimb1 = 0;
> if(isPositiveInteger(document.forms[0].miles2.value))
> var reimb2 = document.forms[0].autoReimb2.value;
> else var reimb2 = 0;
> if(isPositiveInteger(document.forms[0].miles3.value))
> var reimb3 = document.forms[0].autoReimb3.value;
> else var reimb3 = 0;
> if(isPositiveInteger(document.forms[0].miles4.value))
> var reimb4 = document.forms[0].autoReimb4.value;
> else var reimb4 = 0;
> if(isPositiveInteger(document.forms[0].miles5.value))
> var reimb5 = document.forms[0].autoReimb5.value;
> else var reimb5 = 0;
> if(isPositiveInteger(document.forms[0].miles6.value))
> var reimb6 = document.forms[0].autoReimb6.value;
> else var reimb6 = 0;
> if(isPositiveInteger(document.forms[0].miles5.value))
> var reimb7 = document.forms[0].autoReimb7.value;
> else var reimb7 = 0;
>
> var totalauto = (reimb1 * 1) + (reimb2 * 1) + (reimb3 * 1) + (reimb4
> * 1) + (reimb5 * 1) + (reimb6 * 1) + (reimb7 * 1);
> document.forms[0].autotot.value = format(totalauto);
> }
> else eval("document.forms[0]." + nrow + ".value = ''");
> } //End Function

1) Use "document.getElementById" not "eval()".

2) You have "document.forms[0].miles5.value" twice;

3) You should use "myvalue" not "myvalue.value".

5) It can be cleaned up a lot more but the following works; watch for
word-wrap.

<html>
<title>mileage.htm</title>
<script type="text/javascript">
/*
* My function works but there has got to be a way to make a for loop to
* handle this...but I can't get a for loop to work. You can tell, I'm
* not very good at this...help.
*
* "myvalue" is the number of miles the person enters
* "myitem" is the row...there are seven rows where they can list expenses.
* "myvalue" * .375 = amount to be reimbursed
* All the rows are added and placed into the total.
*
*/

function validate() {
// autoReimb(20,2)
for (var i=1; i<8; i++) {
autoReimb(document.getElementById("miles"+i).value ,i)
}
}

function autoReimb(myvalue,myitem){
var nrow = "autoReimb" + myitem;
if(isPositiveInteger(myvalue)){
var amount = myvalue * .375;
formatedamt = format(amount)
//eval("document.forms[0]." + nrow + ".value = formatedamt");
document.getElementById(nrow).value = formatedamt;
if(isPositiveInteger(document.forms[0].miles1.value))
var reimb1 = document.forms[0].autoReimb1.value;
else var reimb1 = 0;
if(isPositiveInteger(document.forms[0].miles2.value))
var reimb2 = document.forms[0].autoReimb2.value;
else var reimb2 = 0;
if(isPositiveInteger(document.forms[0].miles3.value))
var reimb3 = document.forms[0].autoReimb3.value;
else var reimb3 = 0;
if(isPositiveInteger(document.forms[0].miles4.value))
var reimb4 = document.forms[0].autoReimb4.value;
else var reimb4 = 0;
if(isPositiveInteger(document.forms[0].miles5.value))
var reimb5 = document.forms[0].autoReimb5.value;
else var reimb5 = 0;
if(isPositiveInteger(document.forms[0].miles6.value))
var reimb6 = document.forms[0].autoReimb6.value;
else var reimb6 = 0;
if(isPositiveInteger(document.forms[0].miles7.value))
var reimb7 = document.forms[0].autoReimb7.value;
else var reimb7 = 0;
var totalauto = (reimb1 * 1) + (reimb2 * 1) + (reimb3 * 1) + (reimb4
* 1) + (reimb5 * 1) + (reimb6 * 1) + (reimb7 * 1);
document.forms[0].autotot.value = format(totalauto);
}
//else eval("document.forms[0]." + nrow + ".value = ''");
else document.getElementById(nrow).value = "";
}
function format(amount) {
return amount;
}
function isPositiveInteger () {
return true;
}
</script>
<style type="text/css">
..rite { text-align:right; width:40px }
</style>
<body>
<form>
<br><input type="text" name="miles1" value="10" class="rite">
= <input type="text" name="autoReimb1" value="" class="rite">
<br><input type="text" name="miles2" value="20" class="rite">
= <input type="text" name="autoReimb2" value="" class="rite">
<br><input type="text" name="miles3" value="30" class="rite">
= <input type="text" name="autoReimb3" value="" class="rite">
<br><input type="text" name="miles4" value="40" class="rite">
= <input type="text" name="autoReimb4" value="" class="rite">
<br><input type="text" name="miles5" value="50" class="rite">
= <input type="text" name="autoReimb5" value="" class="rite">
<br><input type="text" name="miles6" value="60" class="rite">
= <input type="text" name="autoReimb6" value="" class="rite">
<br><input type="text" name="miles7" value="70" class="rite">
= <input type="text" name="autoReimb7" value="" class="rite">
<br><input type="text" name="autotot">
<input type="button" value="Calc" onclick="validate()">
</form>
</body>
</html>

Michael Winter
Guest
Posts: n/a

 09-03-2004
On Fri, 03 Sep 2004 20:54:49 GMT, McKirahan <(E-Mail Removed)> wrote:

[snip]

> 1) Use "document.getElementById" not "eval()".

Why? Neither is the optimum solution (though gEBI is better).

document.forms[0].elements['miles' + n].value

gEBI requires a recent browser. The line above doesn't.

[snip]

> 3) You should use "myvalue" not "myvalue.value".

It would appear that myvalue is a form control that contains a number. If
it were an actual number, undefined would result from the property access.

[snip]

> 5) It can be cleaned up a lot more but the following works; watch for
> word-wrap.

Yes, it could.

[snip]

function isPosInt(v) {
return /^0|([1-9]\d*)\$/.test(v);
}

function autoReimb(val, itm) {
var e = document.forms[0].elements,
r = 'autoReimb' + itm,
t = 0;

if(isPosInt(val.value)) {
e[r].value = format(val.value * 0.375);
for(var i = 1; i <= 7; ++i) {
if(isPosInt(e['miles' + i].value)) {
t += +e['autoReimb' + i].value;
}
}
e['autotot'].value = format(t);
} else {
e[r].value = '';
}
}

To the OP:

Untested, but it's what I believe it's you were after.

Hope that helps,
Mike

--
Michael Winter
Replace ".invalid" with ".uk" to reply by e-mail.

McKirahan
Guest
Posts: n/a

 09-04-2004
"Michael Winter" <(E-Mail Removed)> wrote in message
newspsdrxjdk4x13kvk@atlantis...
> On Fri, 03 Sep 2004 20:54:49 GMT, McKirahan <(E-Mail Removed)> wrote:
>
> [snip]
>
> > 1) Use "document.getElementById" not "eval()".

>
> Why? Neither is the optimum solution (though gEBI is better).
>
> document.forms[0].elements['miles' + n].value
>
> gEBI requires a recent browser. The line above doesn't.

http://www.jibbering.com/faq/#FAQ4_40

> [snip]
>
> > 3) You should use "myvalue" not "myvalue.value".

>
> It would appear that myvalue is a form control that contains a number. If
> it were an actual number, undefined would result from the property access.
>

"myvalue" is a input parameter to the function:

function autoReimb(myvalue,myitem){

> [snip]
>
> > 5) It can be cleaned up a lot more but the following works; watch for
> > word-wrap.

>
> Yes, it could.
>
> [snip]
>
> function isPosInt(v) {
> return /^0|([1-9]\d*)\$/.test(v);
> }
>
> function autoReimb(val, itm) {
> var e = document.forms[0].elements,
> r = 'autoReimb' + itm,
> t = 0;
>
> if(isPosInt(val.value)) {
> e[r].value = format(val.value * 0.375);
> for(var i = 1; i <= 7; ++i) {
> if(isPosInt(e['miles' + i].value)) {
> t += +e['autoReimb' + i].value;
> }
> }
> e['autotot'].value = format(t);
> } else {
> e[r].value = '';
> }
> }

Good suggestion!

>
> To the OP:
>
> Untested, but it's what I believe it's you were after.
>
> Hope that helps,
> Mike
>
> --
> Michael Winter
> Replace ".invalid" with ".uk" to reply by e-mail.

Michael Winter
Guest
Posts: n/a

 09-04-2004
On Sat, 04 Sep 2004 02:25:40 GMT, McKirahan <(E-Mail Removed)> wrote:

> "Michael Winter" <(E-Mail Removed)> wrote in message
> newspsdrxjdk4x13kvk@atlantis...

[snip]

>> document.forms[0].elements['miles' + n].value
>>
>> gEBI requires a recent browser. The line above doesn't.

>
> http://www.jibbering.com/faq/#FAQ4_40

What's that meant to imply?

[snip]

>> It would appear that myvalue is a form control that contains a number.
>> If it were an actual number, undefined would result from the property
>> access.

>
> "myvalue" is a input parameter to the function:

I know. However, the OP's original code suggests that it is a reference to
a form element, not an actual value. If it were a value, myvalue.value
would evaluate to undefined and I'm sure that if the OP made that mistake,
it would have been explicitly mentioned ("Why does myvalue.value not give
me the value I passed?") or corrected before posting to the group.

If I'm wrong, then you were correct in your first post in that the OP
should have shown the actual function call on the FORM element.

[snip]

Mike

--
Michael Winter
Replace ".invalid" with ".uk" to reply by e-mail.

McKirahan
Guest
Posts: n/a

 09-04-2004
"Michael Winter" <(E-Mail Removed)> wrote in message
newspsdsiucx5x13kvk@atlantis...
> On Sat, 04 Sep 2004 02:25:40 GMT, McKirahan <(E-Mail Removed)> wrote:
>
> > "Michael Winter" <(E-Mail Removed)> wrote in message
> > newspsdrxjdk4x13kvk@atlantis...

>
> [snip]
>
> >> document.forms[0].elements['miles' + n].value
> >>
> >> gEBI requires a recent browser. The line above doesn't.

> >
> > http://www.jibbering.com/faq/#FAQ4_40

>
> What's that meant to imply?
>
> [snip]

Anytime eval() usage is brought up in this ng it gets jumped on.

Here's a recent post which discusses "Why is 'eval' evil?".

From: Lasse Reichstein Nielsen ((E-Mail Removed))
Subject: Re: Why is 'eval' evil?
Original Format
Newsgroups: comp.lang.javascript
Date: 2004-04-04 16:06:50 PST

Reply Via Newsgroup <(E-Mail Removed)> writes:

> I don't use eval alot in my scripts - but I do use it - and since I
> always out to learn more / improve my javascript skills, I'm curious
> why something I thought 'normal' would be considered abnormal.
>
> Can someone put some meat on the bones of 'eval' - its advantages (if
> any) and its disadvantages (which seem great).

As you might guess, it's not the first time someone has questionend
the "eval is evil" slogan It even made the FAQ.
<URL:http://jibbering.com/faq/#FAQ4_40>

The short argument for not using eval is:
"It's shooting pidgeons with cannons."
Sure, it get's the job done, but it's harder to control and takes a
lot more resources than needed, and when it fails, it fails

There is (almost) no situation where there isn't another method that
also does the job, and both more efficiently and a lot safer.

With "more efficient" I mean that it uses fewer resources. The "eval"
function works by first turning its argument into a string, then it
parses the string as a Javascript program and finally it evaluates
it. This is a very expensive operation, and the generality of it is
only needed in rare cases that most people writing web pages will
never meet.

With "safer" I mean that it it is less likely to fail spectacularly.
Since eval can execute arbitrary Javascript expressions, passing the
wrong argument can cause arbitrary errors. On a server, using eval on
a user supplied string is a *very* bad idea. On a client, the main
problem is that the error message is harder to connect to the actual
error, and that, e.g., syntax errors in eval'ed code will only be
detected at run time, not when the script is loaded. So: eval
both introduces more possible errors and hides existing errors.

The two most common (mis)uses of eval are:
1) converting strings to numbers.
There are plenty of dedicated functions and operators for just this
problem: parseInt, parseFloat, Number, the prefix plus operator, most
mathematical operators (string*1,string/1,string-0). Of these, the
prefix plus is the fastest by a small margin. It is roughly *50* times
faster than using eval (in my browser).

2) accessing properties using a computed name.
Example:
eval("document.images.img"+n+".src")
Again it is inefficient, here compared to using square-bracket
notation for property access:
document.images['img'+n].src
It is also error prone. There is no syntax check, and if the variable
"n" contains something you didn't expect, then the failure can be
hard to find. If the property is called something that is not an
identifier (typically "foo[]", used by PHP for form controls, or
perhaps "foo1.1"), then the eval method fails completely.

This is what I take as a sign that the author doesn't know the
language very well. Often the reason for using eval like this is
is a fundamental part of the language. Using eval like this is a
crutch that allows them to stagger along, getting something to
run, whereas knowing the language would let them run

Then there is the third misuse (which the mentioned calendar program
also sufferend from): throwing in an eval "just for good measure",
even though someone who knows the language can see that it doesn't do
anything.

So, eval isn't evil, that's just a good slogan

Eval is *very* slow and dangerously error prone!

For *that* reason, it should be avoided in 99.999% of all cases. As
for the remaining two, when you meet them, you'll hopefully know the
language well enough to be able to recognize them.

/L
--
Lasse Reichstein Nielsen - http://www.velocityreviews.com/forums/(E-Mail Removed)
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleDOM.html>
'Faith without judgement merely degrades the spirit divine.'

Michael Winter
Guest
Posts: n/a

 09-04-2004
On Sat, 04 Sep 2004 12:50:28 GMT, McKirahan <(E-Mail Removed)> wrote:

> "Michael Winter" <(E-Mail Removed)> wrote in message
> newspsdsiucx5x13kvk@atlantis...
>
>> On Sat, 04 Sep 2004 02:25:40 GMT, McKirahan <(E-Mail Removed)> wrote:
>>
>>> http://www.jibbering.com/faq/#FAQ4_40

>>
>> What's that meant to imply?

>
> Anytime eval() usage is brought up in this ng it gets jumped on.

Unless this is purely for the OP's benefit, and I misunderstood, you
haven't grasped my point: I'm not recommending eval (where is an eval call
in my code?), I'm saying that getElementById is not the correct approach.

[snip]

Mike

--
Michael Winter
Replace ".invalid" with ".uk" to reply by e-mail.

Abby Lee
Guest
Posts: n/a

 09-07-2004
You guys are my heros. Thank you.

Thomas 'PointedEars' Lahn
Guest
Posts: n/a

 09-11-2004
McKirahan wrote:

> "Michael Winter" <(E-Mail Removed)> wrote [...]:
>> On Fri, 03 Sep 2004 20:54:49 GMT, McKirahan <(E-Mail Removed)> wrote:
>>
>> [snip]
>>
>> > 1) Use "document.getElementById" not "eval()".

>>
>> Why? Neither is the optimum solution (though gEBI is better).
>>
>> document.forms[0].elements['miles' + n].value

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>> gEBI requires a recent browser. The line above doesn't.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^
> http://www.jibbering.com/faq/#FAQ4_40

You read, but you do not understand.

PointedEars
--
The fat man walks alone at midnight.

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are Off Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post rh0dium Python 10 05-02-2007 05:50 PM Christian Maier C Programming 4 02-18-2007 11:01 AM Peter Olcott C++ 5 12-06-2005 03:54 AM komal C++ 6 01-25-2005 11:13 AM jstreet10 Python 1 12-03-2003 06:27 PM