nsIArray in Firefox 3.6a1pre

Implemented by

@mozilla.org/array;1

 nsIArray

 An indexed collection of elements. Provides basic functionality for
 retrieving elements at a specific position, searching for
 elements. Indexes are zero-based, such that the last element in the
 array is stored at the index length-1.

 For an array which can be modified, see nsIMutableArray below.

 Neither interface makes any attempt to protect the individual
 elements from modification. The convention is that the elements of
 the array should not be modified. Documentation within a specific
 interface should describe variations from this convention.

 It is also convention that if an interface provides access to an
 nsIArray, that the array should not be QueryInterfaced to an
 nsIMutableArray for modification. If the interface in question had
 intended the array to be modified, it would have returned an
 nsIMutableArray!

 null is a valid entry in the array, and as such any nsISupports
 parameters may be null, except where noted.

 @status UNDER_REVIEW

[scriptable, uuid(114744d9-c369-456e-b55a-52fe52880d2d)]

Attributes

 length

 number of elements in the array.

readonly attribute unsigned long length

Methods

 enumerate the array

 @returns a new enumerator positioned at the start of the array
 @throws NS_ERROR_FAILURE if the array is empty (to make it easy
         to detect errors)

nsISimpleEnumerator enumerate()

 indexOf()
 
 Get the position of a specific element. Note that since null is
 a valid input, exceptions are used to indicate that an element
 is not found.
 
 @param startIndex The initial element to search in the array
                   To start at the beginning, use 0 as the
                   startIndex
 @param element    The element you are looking for
 @returns a number >= startIndex which is the position of the
          element in the array.
 @throws NS_ERROR_NOT_FOUND if the element was not in the array.

unsigned long indexOf(in unsigned long startIndex, in nsISupports element)

 queryElementAt()

 Retrieve a specific element of the array, and QueryInterface it
 to the specified interface. null is a valid result for
 this method, but exceptions are thrown in other circumstances
 
 @param index position of element
 @param uuid the IID of the requested interface
 @param result the object, QI'd to the requested interface

 @throws NS_ERROR_NO_INTERFACE when an entry exists at the
         specified index, but the requested interface is not
         available.
 @throws NS_ERROR_ILLEGAL_VALUE when index > length-1

void queryElementAt(in unsigned long index, in nsIIDRef uuid, [iid_is(uuid), retval] out nsQIResult result)