From da78a9e329e272dedb2400b79a3bdeebff387d47 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:42:17 -0500 Subject: initial commit --- .../global_objects/array/length/index.html | 129 +++++++++++++++++++++ 1 file changed, 129 insertions(+) create mode 100644 files/it/web/javascript/reference/global_objects/array/length/index.html (limited to 'files/it/web/javascript/reference/global_objects/array/length') diff --git a/files/it/web/javascript/reference/global_objects/array/length/index.html b/files/it/web/javascript/reference/global_objects/array/length/index.html new file mode 100644 index 0000000000..a36a6b5204 --- /dev/null +++ b/files/it/web/javascript/reference/global_objects/array/length/index.html @@ -0,0 +1,129 @@ +--- +title: Array.length +slug: Web/JavaScript/Reference/Global_Objects/Array/length +translation_of: Web/JavaScript/Reference/Global_Objects/Array/length +--- +
{{JSRef}}
+ +
La proprieta' length setta o restituisce il numero di elementi in un array. E' un intero a 32 bit, sempre maggiore del piu' grande indice dell'array.
+ +
 
+ +
var items = ['shoes', 'shirts', 'socks', 'sweaters'];
+items.length;
+
+// returns 4
+ +

Descrizione

+ +

Puoi impostare la proprietà length di un array per troncare o estendere l'array stesso.

+ +
var a = [1,2,3];
+a.length=2;
+// a is now [1, 2]
+
+a.length = 10
+// a is now [1, 2, undefined × 8]
+
+ +

 

+ +

Esempi

+ +

Iterare su un array

+ +

Nel seguente esempio, l'array numbers viene iterarato e ciascun elemento viene moltiplicato per 2.

+ +
var numbers = [1, 2, 3, 4, 5];
+var length = numbers.length;
+for (var i = 0; i < length; i++) {
+  numbers[i] *= 2;
+}
+// numbers is now [2, 4, 6, 8, 10]
+
+ +

Specifiche

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SpecificheStatoCommento
{{SpecName('ES1')}}{{Spec2('ES1')}}Definizione iniziale.
{{SpecName('ES5.1', '#sec-15.4.5.2', 'Array.length')}}{{Spec2('ES5.1')}} 
{{SpecName('ES6', '#sec-properties-of-array-instances-length', 'Array.length')}}{{Spec2('ES6')}} 
{{SpecName('ESDraft', '#sec-properties-of-array-instances-length', 'Array.length')}}{{Spec2('ESDraft')}} 
+ +

Compatibilità

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{{CompatibilityTable}}
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FeatureChromeFirefox (Gecko)Internet ExplorerOperaSafari
Basic support{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}
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FeatureAndroidChrome for AndroidFirefox Mobile (Gecko)IE MobileOpera MobileSafari Mobile
Basic support{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}
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+ +

 

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