undefined array

[OzThor]

in javascript, is there a way to test if an array is undefined????


eg...
for (var x=0; x<10; x++){
if test_array[x] is undefined then x++
document.write( test_array[x])

if anyone can help, thanks... oh and if you can get the syntex right for me
thanks..

[Grant Wagner]

Re: undefined array

OzThor wrote:
[color=blue]
> in javascript, is there a way to test if an array is undefined????
>
> eg...
> for (var x=0; x<10; x++){
> if test_array[x] is undefined then x++
> document.write( test_array[x])
>
> if anyone can help, thanks... oh and if you can get the syntex right for me
> thanks..[/color]

for (var x = 0; x < 10; x++) {
if (typeof test_array[x] == 'undefined') {
continue;
}

document.write( test_array[x]);
}

or

for (var x = 0; x < 10; x++) {
if (typeof test_array[x] != 'undefined') {
document.write( test_array[x]);
}
}

--
| Grant Wagner <gwagner@agrico reunited.com>

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*

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*

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* http://www.mozilla.org/docs/web-deve...upgrade_2.html

[Lasse Reichstein Nielsen]

Re: undefined array

"OzThor" <ronjeff@ncable .net.au> writes:
[color=blue]
> in javascript, is there a way to test if an array is undefined????[/color]

If it's undefined, then it isn't an array :)
[color=blue]
> eg...
> for (var x=0; x<10; x++){
> if test_array[x] is undefined then x++
> document.write( test_array[x])[/color]

Ah, you want to know whether the array element is undefined.

for (var i=0;i<10;i++) {
if (typeof test_array[i] != "undefined" ) {
document.write( test_array[i]);
}
}

Good luck
/L
--
Lasse Reichstein Nielsen - lrn@hotpop.com
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleD OM.html>
'Faith without judgement merely degrades the spirit divine.'

[Vax]

Re: undefined array

[...]
[color=blue]
> for (var x = 0; x < 10; x++) {
> if (typeof test_array[x] != 'undefined') {
> document.write( test_array[x]);
> }
> }[/color]

or

for(var x,y;x<10;x++)if (test_array[x]!=y)document.wr ite(test_array[x])

(y is declared, but undefined)

v.

[Vax]

Re: undefined array

for(var y,x=0;x<10;x++) if(test_array[x]!=y)document.wr ite(test_array[x])

(y is declared, but undefined)

v.

[Richard Cornford]

Re: undefined array

Vax wrote:[color=blue]
> for(var
> y,x=0;x<10;x++) if(test_array[x]!=y)document.wr ite(test_array[x])
>
> (y is declared, but undefined)[/color]

Using the type-converting comparison - != - means that - null - values
will also be true in - if(test_array[x] != y) - and - null - values are
not undefined. Either a typeof test or the strict (non-type
converting) - !== - comparison are probably the only way to truly
identify undefined array members.

Richard.

[Vax]

Re: undefined array


U¿ytkownik "Richard Cornford" <Richard@litote s.demon.co.uk> napisa³ w
wiadomo¶ci news:c8jkel$nq6 $1$8302bc10@new s.demon.co.uk.. .[color=blue]
> Vax wrote:[color=green]
> > for(var
> > y,x=0;x<10;x++) if(test_array[x]!=y)document.wr ite(test_array[x])
> >
> > (y is declared, but undefined)[/color]
>
> Using the type-converting comparison - != - means that - null - values
> will also be true in - if(test_array[x] != y) - and - null - values are
> not undefined.[/color]

yes, but try:
javascript:x=nu ll;alert(x==und efined)
javascript:var x=0;alert(x==un defined)
javascript:var x=false;alert(x ==undefined)

problem is only(?) with "null"...

v.

[Richard Cornford]

Re: undefined array

Vax wrote:[color=blue]
> "Richard Cornford" wrote:[color=green]
>> Vax wrote:[color=darkred]
>>> for(var
>>> y,x=0;x<10;x++) if(test_array[x]!=y)document.wr ite(test_array[x])
>>>
>>> (y is declared, but undefined)[/color]
>>
>> Using the type-converting comparison - != - means that - null -
>> values will also be true in - if(test_array[x] != y) - and - null -
>> values are not undefined.[/color]
>
> yes, but try:
> javascript:x=nu ll;alert(x==und efined)
> javascript:var x=0;alert(x==un defined)
> javascript:var x=false;alert(x ==undefined)
>
> problem is only(?) with "null"...[/color]

That is what I said, but - null - and - undefined - are still distinct.

Richard.