Item (UnicodeNamedArraylist property): Difference between revisions

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{{Template:UnicodeNamedArraylist:Item subtitle}}
{{Template:UnicodeNamedArraylist:Item subtitle}}
 
This ReadWrite property returns or sets the value of the item that has the
<!-- This is very close to the same method's page for these classes:
specified subscript name in the UnicodeNamedArraylist.
      NamedArraylist
 
      FloatNamedArraylist
For additional comments about the Item method in collections,
    Many changes should be reflected to all three method's pages -->
see [[Collections#Coding considerations for collections|Coding considerations for collections]].
<var>Item</var> is a ReadWrite property which returns or sets the value of the item that has the given name in the <var>UnicodeNamedArraylist</var>.
For additional comments about the <var>Item</var> method in collections, see [[Collections#Coding considerations for collections|"Coding considerations for collections"]].
==Syntax==
==Syntax==
{{Template:UnicodeNamedArraylist:Item syntax}}
{{Template:UnicodeNamedArraylist:Item syntax}}
===Syntax terms===
===Syntax terms===
<dl>
<dt><i>%item</i>
<!-- This is very close to the same method's page for these classes:
<dd>A variable of the same
      NamedArraylist
type as specified on the ''%unamrayl'' declaration
      FloatNamedArraylist
to contain the value of the specified ''%unamrayl'' item.
    Many changes should be reflected to all three method's pages -->
Or a variable or value of the same
type as specified on the ''%unamrayl'' declaration
<table class="syntaxTable">
to be assigned to the specified ''%unamrayl'' item.
<tr><th>%currentItem</th>
<dt><i>%unamrayl</i>
<td>A variable of the same type as specified on the <var class="term">uniNal</var> declaration to contain the value of the specified <var class="term">uniNal</var> item.</td></tr>
<dd>A UnicodeNamedArraylist object.
<tr><th>uniNal</th>
<dt><i>name</i>
<td>A <var>UnicodeNamedArraylist</var> object. </td></tr>
<dd>A Unicode string that serves as a subscript to identify
<tr><th>unicode</th>
a ''%unamrayl'' item.
<td>A Unicode string that serves as a subscript to identify a <var class="term">uniNal</var> item.</td></tr>
 
<tr><th>newItem</th>
</dl>
<td>A value of the same type as specified on the <var class="term">uniNal</var> declaration to be assigned to the specified <var class="term">uniNal</var> item. </td></tr>
</table>
==Usage notes==
==Usage notes==
<!-- This is very close to the same method's page for these classes:
      NamedArraylist
      FloatNamedArraylist
    Many changes should be reflected to all three method's pages -->
<ul>
<ul>
<li>The <tt>Item</tt> keyword is not required.
<li>The <var>Item</var> keyword is not required. For example, in the first of the [[UnicodeNamedArraylist class#Examples|"Examples"]] on the <var>UnicodeNamedArraylist</var> class page, the following statement:
For example, in the request in the
<p class="code">%k('&amp;sect;Apr':u) = 'Leo'</p>
[[UnicodeNamedArraylist class]] example, <tt>%k('&amp;sect;Apr':u) = 'Leo'</tt>, for
is equivalent to:
instance, is equivalent to:
<p class="code">%k:Item('&amp;sect;Apr':u) = 'Leo'
<pre style="xmp">
</p>
    %k:Item('&amp;sect;Apr':u) = 'Leo'
<li>If the <var>Item</var> property is being set and there is already an item on the <var>UnicodeNamedArraylist</var> that has the specified name, that item is replaced. If the <var>Item</var> property is being set and there is no item on the <var>UnicodeNamedArraylist</var> that has the indicated name, the item is added.
</pre>
<li>If the <var>Item</var> property is being retrieved and there is no item on the <var>UnicodeNamedArraylist</var> that has the indicated name, the result is one of the following actions:
<li>If the Item property is being set and there is already an item
on the UnicodeNamedArraylist that has the specified name, that item is replaced.
 
If the Item property is being set and there is no item on the UnicodeNamedArraylist
that has the indicated name, the item is added.
 
If the Item property is being retrieved and there is no item on the UnicodeNamedArraylist
that has the indicated name, the result is one of the following actions:
<ul>
<ul>
<li>The request is cancelled if the
<li>If the <var>[[UseDefault (UnicodeNamedArraylist property)|UseDefault]]</var> property value is <code>False</code>:
[[UseDefault (UnicodeNamedArraylist property)|UseDefault]] property value is <tt>False</tt>.
<ul>
<li>The [[Default (UnicodeNamedArraylist property)|Default]] value is returned if the
<li>Under <var>Sirius Mods</var> version 8.0 and later an <var>[[ItemNotPresent class|ItemNotPresent exception]]</var> is thrown.
UseDefault property is <tt>True</tt>.
<li>Under <var>Sirius Mods</var> version 7.9 and earlier the request is cancelled.
</ul>
</ul>
<li>As shown in the example in the [[UnicodeNamedArraylist class]] article,
<li>The <var>[[Default (UnicodeNamedArraylist property)|Default]]</var> value is returned if the <var>UseDefault</var> property is <code>True</code>.
UnicodeNamedArraylist items are ordered alphabetically by their subscript names.
Accordingly, the Item method takes a Unicode string ''name'' argument.
The ItemByNumber method, described below,
lets you retrieve or set an item using the item's ordinal number.
The [[NameByNumber (UnicodeNamedArraylist property)|NameByNumber]] function
lets you retrieve or set an item using the item's subscript name.
</ul>
</ul>
Regardless of the value of <var>UseDefault</var>, the presence of the item with the indicated name can be checked using the <var>[[Number (UnicodeNamedArraylist function)|Number]]</var> function, for example:
<p class="code">%num = %myLis:number(%key)
if %num then %name = %myLis:[[ItemByNumber (UnicodeNamedArraylist property)|itemByNumber]](%num)
...
</p>
<li>As shown in the first of the [[UnicodeNamedArraylist class#Examples|"Examples"]] on the <var>UnicodeNamedArraylist</var> class page,
<var>UnicodeNamedArraylist</var> items are ordered alphabetically by their subscript names.
</ul>
==See also==
==See also==
<!-- This is very close to the same method's page for these classes:
      NamedArraylist
      FloatNamedArraylist
    Many changes should be reflected to all three method's pages -->
<ul><li>The <var>[[ItemByNumber_(GenericNamedArraylist_property)|ItemByNumber]]</var> property lets you retrieve or set an item using the item's ordinal number.
<li>The <var>[[NameByNumber (UnicodeNamedArraylist function)|NameByNumber]]</var> function lets you retrieve an item's name using the item's ordinal number.
<li>The <var>[[Number (UnicodeNamedArraylist function)|Number]]</var> function lets you retrieve an item's ordinal number using the item's name; it can be useful for determining whether an item exists for a specified name.
</ul>
{{Template:UnicodeNamedArraylist:Item footer}}
{{Template:UnicodeNamedArraylist:Item footer}}

Latest revision as of 16:44, 5 August 2012

Value of named item (UnicodeNamedArraylist class)


Item is a ReadWrite property which returns or sets the value of the item that has the given name in the UnicodeNamedArraylist.

For additional comments about the Item method in collections, see "Coding considerations for collections".

Syntax

%currentItem = uniNal:Item( unicode) uniNal:Item( unicode) = newItem Throws ItemNotPresent

Syntax terms

%currentItem A variable of the same type as specified on the uniNal declaration to contain the value of the specified uniNal item.
uniNal A UnicodeNamedArraylist object.
unicode A Unicode string that serves as a subscript to identify a uniNal item.
newItem A value of the same type as specified on the uniNal declaration to be assigned to the specified uniNal item.

Usage notes

  • The Item keyword is not required. For example, in the first of the "Examples" on the UnicodeNamedArraylist class page, the following statement:

    %k('&sect;Apr':u) = 'Leo'

    is equivalent to:

    %k:Item('&sect;Apr':u) = 'Leo'

  • If the Item property is being set and there is already an item on the UnicodeNamedArraylist that has the specified name, that item is replaced. If the Item property is being set and there is no item on the UnicodeNamedArraylist that has the indicated name, the item is added.
  • If the Item property is being retrieved and there is no item on the UnicodeNamedArraylist that has the indicated name, the result is one of the following actions:
    • If the UseDefault property value is False:
      • Under Sirius Mods version 8.0 and later an ItemNotPresent exception is thrown.
      • Under Sirius Mods version 7.9 and earlier the request is cancelled.
    • The Default value is returned if the UseDefault property is True.

    Regardless of the value of UseDefault, the presence of the item with the indicated name can be checked using the Number function, for example:

    %num = %myLis:number(%key) if %num then %name = %myLis:itemByNumber(%num) ...

  • As shown in the first of the "Examples" on the UnicodeNamedArraylist class page, UnicodeNamedArraylist items are ordered alphabetically by their subscript names.

See also

  • The ItemByNumber property lets you retrieve or set an item using the item's ordinal number.
  • The NameByNumber function lets you retrieve an item's name using the item's ordinal number.
  • The Number function lets you retrieve an item's ordinal number using the item's name; it can be useful for determining whether an item exists for a specified name.