From da78a9e329e272dedb2400b79a3bdeebff387d47 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:42:17 -0500 Subject: initial commit --- .../reference/global_objects/array/keys/index.html | 74 ++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 files/it/web/javascript/reference/global_objects/array/keys/index.html (limited to 'files/it/web/javascript/reference/global_objects/array/keys') diff --git a/files/it/web/javascript/reference/global_objects/array/keys/index.html b/files/it/web/javascript/reference/global_objects/array/keys/index.html new file mode 100644 index 0000000000..78212d221f --- /dev/null +++ b/files/it/web/javascript/reference/global_objects/array/keys/index.html @@ -0,0 +1,74 @@ +--- +title: Array.prototype.keys() +slug: Web/JavaScript/Reference/Global_Objects/Array/keys +translation_of: Web/JavaScript/Reference/Global_Objects/Array/keys +--- +
{{JSRef}}
+ +

Il metodo keys() ritorna un nuovo oggetto Array Iterator contenente le chiavi di ogni indice dell'array.

+ +
var arr = ['a', 'b', 'c'];
+var iterator = arr.keys();
+
+console.log(iterator.next()); // { value: 0, done: false }
+console.log(iterator.next()); // { value: 1, done: false }
+console.log(iterator.next()); // { value: 2, done: false }
+console.log(iterator.next()); // { value: undefined, done: true }
+
+ +

Sintassi

+ +
arr.keys()
+ +

Valore di ritorno

+ +

Un nuovo oggetto {{jsxref("Array")}}.

+ +

Esempi

+ +

I Key iterator non ignorano gli elementi vuoti

+ +
var arr = ['a', , 'c'];
+var sparseKeys = Object.keys(arr);
+var denseKeys = [...arr.keys()];
+console.log(sparseKeys); // ['0', '2']
+console.log(denseKeys);  // [0, 1, 2]
+
+ +

Specifiche

+ + + + + + + + + + + + + + + + + + + +
SpecificaStatoCommenti
{{SpecName('ES2015', '#sec-array.prototype.keys', 'Array.prototype.keys')}}{{Spec2('ES2015')}}Initial definition.
{{SpecName('ESDraft', '#sec-array.prototype.keys', 'Array.prototype.keys')}}{{Spec2('ESDraft')}} 
+ +

Browser compatibility

+ +
+ + +

{{Compat("javascript.builtins.Array.keys")}}

+
+ +

Vedi anche

+ + -- cgit v1.2.3-54-g00ecf