stepping threw an array

[Abby Lee]

I've created the following array and want to be able to process each
indivisual object whenever my function is called. Is this best done
with a "foreach"? I don't see a foreach in my javascript book...is
there another way to step threw an array to process each item?

var trvtps = new Array('autoReim b','airRail','c ar','taxi','lod ge','meals','mi sc');

[Lasse Reichstein Nielsen]

Re: stepping threw an array

abbylee26@hotma il.com (Abby Lee) writes:
[color=blue]
> I've created the following array and want to be able to process each
> indivisual object whenever my function is called. Is this best done
> with a "foreach"? I don't see a foreach in my javascript book...is
> there another way to step threw an array to process each item?
>
> var trvtps = new Array('autoReim b','airRail','c ar','taxi','lod ge','meals','mi sc');[/color]

There are two ways:
---
for (var i = 0; i < trvtps.length; i++) {
var trvtp = trvtps[i];
// something with trvtp.
}
---
and
---
for (var i in trvtps) {
var trvtp = trvtps[i];
// something with trvtp.
}
---

The former is targeted at an array (something with a length and
integer indices) whereas the latter works on any object and
iterates all enumerable properties, not only integer ones.

As long as you haven't added properties to "Object.prototy pe",
"Array.prototyp e" or "trvtps" itself, then only the integer properties
are properties of the array.

If you have an array where not all positions have a value, the
for(...in...) will skip these positions, whereas the incrementing
for loop will access all positions less than the length.

/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.'

[Lee]

Re: stepping threw an array

Abby Lee said:[color=blue]
>
>I've created the following array and want to be able to process each
>indivisual object whenever my function is called. Is this best done
>with a "foreach"? I don't see a foreach in my javascript book...is
>there another way to step threw an array to process each item?
>
>var trvtps = new
>Array('autoRei mb','airRail',' car','taxi','lo dge','meals','m isc');[/color]

The length attribute of the array tells you how many entries
it contains. They will be numbered from 0 to length-1.

for(var i=0;i<trvtps.le ngth;i++){
alert(trvtps[i]);
}

[Mick White]

Re: stepping threw an array

Abby Lee wrote:
[color=blue]
> I've created the following array and want to be able to process each
> indivisual object whenever my function is called. Is this best done
> with a "foreach"? I don't see a foreach in my javascript book...is
> there another way to step threw an array to process each item?
>
> var trvtps = new Array('autoReim b','airRail','c ar','taxi','lod ge','meals','mi sc');[/color]
t=trvtps.length ;
while(t--){myProcessFunc tion(trvtps[t])}
Mick

[Evertjan.]

Re: stepping threw an array

Mick White wrote on 09 sep 2004 in comp.lang.javas cript:
[color=blue]
> t=trvtps.length ;
> while(t--){myProcessFunc tion(trvtps[t])}[/color]

var t=0;
while(t<trvtps. length)
myProcessFuncti on(trvtps[t++])


--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress,
but let us keep the discussions in the newsgroup)

[Mick White]

Re: stepping threw an array

Evertjan. wrote:
[color=blue]
> Mick White wrote on 09 sep 2004 in comp.lang.javas cript:
>[color=green]
>>t=trvtps.leng th;
>>while(t--){myProcessFunc tion(trvtps[t])}[/color][/color]
[color=blue]
> var t=0;
> while(t<trvtps. length)
> myProcessFuncti on(trvtps[t++])
>[/color]
Both approaches work equally well. Did you try both?
Mick

[Evertjan.]

Re: stepping threw an array

Mick White wrote on 09 sep 2004 in comp.lang.javas cript:
[color=blue]
> Evertjan. wrote:
>[color=green]
>> Mick White wrote on 09 sep 2004 in comp.lang.javas cript:
>>[color=darkred]
>>>t=trvtps.len gth;
>>>while(t--){myProcessFunc tion(trvtps[t])}[/color][/color]
>[color=green]
>> var t=0;
>> while(t<trvtps. length)
>> myProcessFuncti on(trvtps[t++])
>>[/color]
> Both approaches work equally well. Did you try both?[/color]

Who are you asking, Mick?

I just like to have my pointers increasing and minimizing superfluous ()


--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress,
but let us keep the discussions in the newsgroup)