sorting an array

[Michael Hill]

If I have an array defined like this:

var list = [
["1","359"," No a Test xxxxxxxxxxxxxxx ","
0","08/18/2003","Approved "],
["2","268"," test character fields for 500
","129","07/14/2003","Approved "],
["3","288","text area filled XXXXXXXx","
0","07/15/2003","Approved "]
];

How would I sort it by the 3th column?

Mike

[Lasse Reichstein Nielsen]

Re: sorting an array

Michael Hill <hillmw@ram.lmt as.lmco.com> writes:
[color=blue]
> If I have an array defined like this:
>
> var list = [
> ["1","359"," No a Test xxxxxxxxxxxxxxx ","
> 0","08/18/2003","Approved "],[/color]

Please avoid line breaks when posting code. The code, as posted, is
invalid.

Try this:
---
function compare(a,b) {
if (a<b) {return -1;}
if (a>b) {return 1;}
return 0;
}

var sortedList = list.sort(funct ion(a,b){return compare(a[2],b[2]);});
---

/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.'

[Douglas Crockford]

Re: sorting an array

> If I have an array defined like this:[color=blue]
>
> var list = [
> ["1","359"," No a Test xxxxxxxxxxxxxxx ","
> 0","08/18/2003","Approved "],
> ["2","268"," test character fields for 500
> ","129","07/14/2003","Approved "],
> ["3","288","text area filled XXXXXXXx","
> 0","07/15/2003","Approved "]
> ];
>
> How would I sort it by the 3th column?[/color]

You can pass a function to the array.sort(fn) method.

list.sort(funct ion (a, b) {
if (a[2] == b[2]) {
return 0;
}
if (a[2] < b[2]) {
return -1;
}
return 1;
});

// 15.4.4.11

http://www.crockford.com/javascript/survey.html

[Evertjan.]

Re: sorting an array

Douglas Crockford wrote on 01 dec 2003 in comp.lang.javas cript:
[color=blue]
> list.sort(funct ion (a, b) {
> if (a[2] == b[2]) {
> return 0;
> }
> if (a[2] < b[2]) {
> return -1;
> }
> return 1;
> });
>[/color]

In short:

list.sort(
function(a,b) {
return (a[2]>b[2])?1:(a[2]<b[2])?-1:0
}
);


--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

[Douglas Crockford]

Re: sorting an array

> > list.sort(funct ion (a, b) {[color=blue][color=green]
> > if (a[2] == b[2]) {
> > return 0;
> > }
> > if (a[2] < b[2]) {
> > return -1;
> > }
> > return 1;
> > });
> >[/color]
>
> In short:
>
> list.sort(
> function(a,b) {
> return (a[2]>b[2])?1:(a[2]<b[2])?-1:0
> }
> );[/color]

Or shorter,

list.sort(funct ion(a,b){return (a[2]>b[2])?1:(a[2]<b[2])?-1:0});

[Lasse Reichstein Nielsen]

Re: sorting an array

"Douglas Crockford" <nospam@covad.n et> writes:
[color=blue]
> Or shorter,
>
> list.sort(funct ion(a,b){return (a[2]>b[2])?1:(a[2]<b[2])?-1:0});[/color]

Or even shorter, and much uglier,
list.sort(funct ion(a,b){return a[2]<b[2]?-1:+(a[2]>b[2]);});

And the original was still by far the most readable.
/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.'

[Evertjan.]

Re: sorting an array

Douglas Crockford wrote on 01 dec 2003 in comp.lang.javas cript:
[color=blue][color=green][color=darkred]
>> > list.sort(funct ion (a, b) {
>> > if (a[2] == b[2]) {
>> > return 0;
>> > }
>> > if (a[2] < b[2]) {
>> > return -1;
>> > }
>> > return 1;
>> > });
>> >[/color]
>>
>> In short:
>>
>> list.sort(
>> function(a,b) {
>> return (a[2]>b[2])?1:(a[2]<b[2])?-1:0
>> }
>> );[/color]
>
> Or shorter,
>
> list.sort(funct ion(a,b){return (a[2]>b[2])?1:(a[2]<b[2])?-1:0});[/color]

Even shorter:

list.sort(funct ion(a,b){return (c=a[2]-b[2])?(c>0)?1:-1:0});

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

[Douglas Crockford]

Re: sorting an array

> >> > list.sort(funct ion (a, b) {[color=blue][color=green][color=darkred]
> >> > if (a[2] == b[2]) {
> >> > return 0;
> >> > }
> >> > if (a[2] < b[2]) {
> >> > return -1;
> >> > }
> >> > return 1;
> >> > });
> >> >
> >>
> >> In short:
> >>
> >> list.sort(
> >> function(a,b) {
> >> return (a[2]>b[2])?1:(a[2]<b[2])?-1:0
> >> }
> >> );[/color]
> >
> > Or shorter,
> >
> > list.sort(funct ion(a,b){return (a[2]>b[2])?1:(a[2]<b[2])?-1:0});[/color]
>
> Even shorter:
>
> list.sort(funct ion(a,b){return (c=a[2]-b[2])?(c>0)?1:-1:0});[/color]

That assumes that the values are numbers. If they are, then

list.sort(funct ion(a,b){return a[2] - b[2]});

[Evertjan.]

Re: sorting an array

Lasse Reichstein Nielsen wrote on 02 dec 2003 in comp.lang.javas cript:
[color=blue][color=green]
>> Or shorter,
>>
>> list.sort(funct ion(a,b){return (a[2]>b[2])?1:(a[2]<b[2])?-1:0});[/color]
>
> Or even shorter, and much uglier,
> list.sort(funct ion(a,b){return a[2]<b[2]?-1:+(a[2]>b[2]);});[/color]

Haha:

list.sort(funct ion(a,b){return +((c=a[2]-b[2])>0)-(c<0)});

Ugliness is a joy forever in the hand of the beholder.

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

[Lasse Reichstein Nielsen]

Re: sorting an array

"Evertjan." <exjxw.hannivoo rt@interxnl.net > writes:
[color=blue]
> list.sort(funct ion(a,b){return +((c=a[2]-b[2])>0)-(c<0)});[/color]

That requires a[2] and b[2] to be numbers. Comparison works for
strings too, and the original poster's example had strings at offset
2.

(And as it was pointed out, if they are numbers,
list.sort(funct ion(a,b){return a[2]-b[2];});
is sufficient).

/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.'

[Evertjan.]

Re: sorting an array

Lasse Reichstein Nielsen wrote on 02 dec 2003 in comp.lang.javas cript:
[color=blue]
> And as it was pointed out, if they are numbers,
> list.sort(funct ion(a,b){return a[2]-b[2];});
> is sufficient[/color]

True.

Not according to the specs, but I do not find that very important.

==============

So for strings, and without an if or ?: clause, we are stuck with:

return +(a[2]<b[2])-(a[2]>b[2])

==============

Internally machine coded in a comparison, the three possiblilities must be
available as a "triary" and reduced to a binary output. Silly higher
languages.

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

[Lasse Reichstein Nielsen]

Re: sorting an array

"Evertjan." <exjxw.hannivoo rt@interxnl.net > writes:
[color=blue]
> So for strings, and without an if or ?: clause, we are stuck with:
>
> return +(a[2]<b[2])-(a[2]>b[2])[/color]

That's cute!
[color=blue]
> Internally machine coded in a comparison, the three possiblilities must be
> available as a "triary" and reduced to a binary output. Silly higher
> languages.[/color]

I miss Perl's <=> operator :)

/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.'

[Lasse Reichstein Nielsen]

Re: sorting an array

Lasse Reichstein Nielsen <lrn@hotpop.com > writes:
[color=blue]
> "Evertjan." <exjxw.hannivoo rt@interxnl.net > writes:[/color]
[color=blue][color=green]
>> return +(a[2]<b[2])-(a[2]>b[2])[/color]
>
> That's cute![/color]

It should actually be the other way around (to sort increasingly):
return (a[2]>b[2])-(a[2]<b[2]);
(and you can omit the +, since "-" converts both arguments to numbers)

/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.'

[Dr John Stockton]

Re: sorting an array

JRS: In article <Xns944563C16B7 FDeejj99@194.10 9.133.29>, seen in
news:comp.lang. javascript, Evertjan. <exjxw.hannivoo rt@interxnl.net >
posted at Tue, 2 Dec 2003 08:48:22 :-
[color=blue]
>So for strings, and without an if or ?: clause, we are stuck with:
>
>return +(a[2]<b[2])-(a[2]>b[2])[/color]

For those using W3's TIDY to check the Web page, and I recommend doing
so, that needs to be at least
return +(a[2]< b[2])-(a[2]>b[2])

in order not to risk confusing TIDY (if using the same version as I do).
The combination LessThan Letter seems to be taken as requiring a closing
GreaterThan, unless the traditional <!-- and --> are used.

Nicer:
return +( a[2] < b[2] ) - ( a[2] > b[2] )

However, I do not see how the + is needed.

--
© John Stockton, Surrey, UK. ?@merlyn.demon. co.uk Turnpike v4.00 IE 4 ©
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