for loop

**Dietmar Meier** · Jul 23 '05, 07:05 PM

Re: for loop

david.jebo@gmai l.com wrote:
[color=blue]
> Can anyone help me with writing a loop?[/color]

<script type="text/javascript">
function calculator() { // you didn't use arguments, so I dropped them
var a, b, i, oBox, oForm, aElems, oSumElem;
if ((oForm = document.forms["chmod"]) && (aElems = oForm.elements) ) {
for (i=1, a=0, b=0; i<6; i++) {
if ((oBox = aElems["Matching" + i])) {
if (oBox.checked) {
a += oBox.value * 1;
}
else {
b += oBox.value * 1;
}
}
}
if ((oSumElem = aElems["Matching_Funds "])) {
oSumElem.value = a;
}

if ((oSumElem = aElems["Other_Fund s"]) {
oSumElem.value = b;
}
}
}
</script>

BTW: for selects better use onchange, not onblur.

ciao, dhgm

**alperadatoz@gmail.com** · Jul 23 '05, 07:05 PM

Re: for loop

Hi David,

You can use the calculator function like this;

function calculator(user , number){
var a=0;
var b=0;

for(i=1; i<6; i++) {
if(eval("docume nt.chmod.Matchi ng"+i).checked= =true) {
a +=(eval("docume nt.chmod.textFi eld"+i+".value" )*1);
}
else {
b +=(eval("docume nt.chmod.textFi eld"+i+".value" )*1);
}
}
document.chmod. Matching_Funds. value=a
document.chmod. Other_Funds.val ue=b

}

**Lee** · Jul 23 '05, 07:05 PM

Re: for loop

alperadatoz@gma il.com said:

[color=blue]
>function calculator(user , number){
> var a=0;
> var b=0;
>
> for(i=1; i<6; i++) {
> if(eval("docume nt.chmod.Matchi ng"+i).checked= =true) {
> a +=(eval("docume nt.chmod.textFi eld"+i+".value" )*1);
> }
> else {
> b +=(eval("docume nt.chmod.textFi eld"+i+".value" )*1);
> }
> }
> document.chmod. Matching_Funds. value=a
> document.chmod. Other_Funds.val ue=b
>
>}[/color]

[Most of the problems I'm pointing out appear in the original code,
but it's easier to respond here]

1. Why are user and number passed to this function?

2. You don't need to use eval() in any of these cases.
3. You don't need to compare a boolean value to true:

if(document.chm od.elements["Matching"+ i].checked) {

4. The unary + operator is more efficient for converting strings to numbers.

a += +document.chmod .elements["textField" +i].value;

5. The function should be invoked by the onChange handler,
rather than by the onBlur handler.

6. You should provide some error checking for non-numeric entries.
Probably something better than:

if(isNaN(a)) {
document.chmod. Matching_Funds. value="Error - non-numeric entry";
} else {
document.chmod. Matching_Funds. value=a;
}

7. Don't forget to repeat your calculations on the server side.
Never trust dollar values computed on the user's machine.

**Randy Webb** · Jul 23 '05, 07:05 PM

Re: for loop

alperadatoz@gma il.com wrote:[color=blue]
> Hi David,
>
> You can use the calculator function like this;
>
> function calculator(user , number){
> var a=0;
> var b=0;
>
> for(i=1; i<6; i++) {
> if(eval("docume nt.chmod.Matchi ng"+i).checked= =true) {[/color]

eval? <gag>

if (document.chmod .elements['Matching' + i].checked)

Look Ma! No eval.....

There is also no reason to check for ==true since you are converting
boolean to boolean so just check your boolean in a boolean statement.
[color=blue]
> a +=(eval("docume nt.chmod.textFi eld"+i+".value" )*1);[/color]

a += +document.chmod .elements['textField'+i].value;
[color=blue]
> }
> else {
> b +=(eval("docume nt.chmod.textFi eld"+i+".value" )*1);[/color]

b += +document.chmod .elements['textField'+i].value;

Before using eval where it isn't needed, one should (at minimum) consult
this groups FAQ, where the accessing of form elements is covered very well.

--
Randy
comp.lang.javas cript FAQ - http://jibbering.com/faq & newsgroup weekly

for loop

for loop

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