En l'occurence c'est avec le JSONstringifier (http://json.org/js.html) qui comporte cette fonction :
Array.prototype.toJSONString = function () { ... }
Le résultat c'est que tous mes tableaux ont une case en plus, dont le contenu est "toJSONString" !
J'avais eu exactement le même problème en utilisant cette excellent classe où il y avait
function inArray(text)
{
for (a=0;a<this.length;a++)
{
if(this[a] == text)
{
return true;
}
}
}
Array.prototype.inArray = inArray;
et ça rajoutait une case avec "inArray" à tous mes tableaux.
Arto_8000 disait de rajouter une condition dans les boucles for(i in array) pour zapper la case en question, mais ce n'est pas envisageable comme solution.
Re,
et bien tu n'as pas le choix, c'est le seul moyen....
Tien voilà ce qu'en dis l'auteur de la librairie prototypejs:
Many JavaScript authors have been misled into using the
for
…
in
JavaScript construct to loop over array elements. This kind of code just won’t work with Prototype.
You see, the ECMA 262 standard, which defines ECMAScript 3rd edition, supposedly implemented by all major browsers including MSIE, defines numerous methods on
Array
(§15.4.4), including such nice methods as
concat
,
join
,
pop
and
push
, to name but a few among the ten methods specified.
This same standard explicitely defines that the
for
…
in
construct (§12.6.4) exists to enumerate the properties of the object appearing on the right side of the
in
keyword. Only properties specifically marked as non-enumerable are ignored by such a loop. By default, the prototype and the
length
properties are so marked, which prevents you from enumerating over array methods when using
for
…
in
. This comfort led developers to use
for
…
in
as a shortcut for indexing loops, when it is not its actual purpose.
However, Prototype has no way to mark the methods it adds to
Array.prototype
as non-enumerable. Therefore, using
for
…
in
on arrays when using Prototype will enumerate all extended methods as well, such as those coming from the
myArray.each(function(item) {
// Your code working on item here...
});
This side-effect enforcement of the true purpose of
for
…
in
is actually not so much of a burden: as you’ll see, most of what you
used to loop over arrays for can be concisely done using the new
methods provided by
A note on performance
Should you have a very large array, using iterators with lexical closures (anonymous functions that you pass to the iterators, that get invoked at every loop iteration), such as
),
may yield unsatisfactory performance. In such cases, you’re better off
writing manual indexing loops, but take care then to cache the
length
property and use the prefix
++
operator:
// Custom loop with cached length property: maximum full-loop performance on very large arrays!for(var index 0, len myArray.length; index < len; ++index) {
var item = myArray[index];
// Your code working on item here...
}
Bonjour,
ce n'est pas un problème, c'est la nature même du javascript où tout est tableau.
Ainsi un objet est un tablau...
Pour parcourir un tableau la bonne syntaxe est:for(var i 0, length array.length; i < length; i++){
....
}
