Denis McMahon wrote:
> On Fri, 14 Jun 2013 00:15:37 -0700, JT wrote:
>> Can i somehow tell which javascript elements to shift?
>> Is something like following possible element[i].shift()
>>
>> Many times one want to change items not necessarily at element[0], and
>> sometimes you want to swap them with another index.
>>
>> I think the shift function should take one or two parameters or a new
>> function should be constructed.
>>
>> element [x][y].swap();
>>
>> It is not hard to swap elements but it make more sense then the
>> noneflexible shift() function.
>
> If you want to swap elements x and y in an array:
>
> element [x][y].swap();
>
> makes no sense.
ACK.
> Your function would have to be something like:
>
> array.swap_elements(x,y);
>
> But why would you ever need to do this except in the context of sorting?
One can never know.
> An array is either ordered or unordered - if it's unordered it doesn't
> matter what order the elements are in,
Your logic is flawed – again.
> and if you want it ordered according to some specific algorithm, just
> write a custom sort function and sort with it:
>
> array.sort(sortfunction);
>
> where:
>
> sortfunction( a, b ) {}
>
> returns <0 if a comes first, >0 if b comes first, 0 if they're equal.
As that is a syntax error, it does not return anything. Functions are
declared with
function identifier (parameter1, parameter2/*, …*/)
{
// …
}
and called with
identifier(argument1, argument2/* , … */);
[The number of arguments does not need to match the number of formal
parameters. If an argument is passed for which there is no parameter, its
value is available via a numeric zero-based property of the “arguments”
object in the function context. If no argument is passed for a formal
parameter, it is initialized with the “undefined” value. Also, the value of
the “arguments.length” property yields the number of arguments that have
been passed to a function.]
It is not always necessary to declare a function as there are function
expressions:
array.sort(function (a, b) {
// …
});
or
var sortNumerically = function (a, b) {
return a - b;
};
array.sort(sortNumerically);
A function declaration and the latter approach has the advantage that an
unchanging function needs only be created once. The advantage of a function
expression over a function declaration primarily is that its evaluation
result (a Function instance reference) can be assigned as value to any
property, allowing for namespacing.
[It is strongly recommended to define and use this trivial sort function, as
the default is implementation-dependent and may sort the elements as string
values instead.]
See also: <
http://PointedEars.de/es-matrix#features>
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