1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
<?xml version="1.0" encoding="UTF-8"?>
<helpdocument version="1.0">
<!--
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
-->
<meta>
<topic id="collectionobject" indexer="include" status="PUBLISH">
<title id="tit" xml-lang="en-US">Collection Object</title>
<filename>/text/sbasic/shared/collection.xhp</filename>
</topic>
</meta>
<body>
<section id="collection_desc">
<bookmark xml-lang="en-US" branch="index" id="bm_id3149205">
<bookmark_value>Collection Object</bookmark_value>
</bookmark>
<bookmark xml-lang="en-US" localize="false" branch="index" id="bm_id3149225890">
<bookmark_value>Collection;Count</bookmark_value>
</bookmark>
<h1 id="hd_id791633472607429"><variable id="Collection_h1"><link href="text/sbasic/shared/collection.xhp">Collection Object</link></variable></h1>
<paragraph role="paragraph" id="par_id581633961735332">Collections can be used to store items of different types. Each item can be accessed by its index or by an optional key associated with it.</paragraph>
</section>
<paragraph role="paragraph" id="par_id131633961959816">A <literal>Collection</literal> object has the following methods:</paragraph>
<list type="unordered">
<listitem>
<paragraph id="par_id331633962000259" role="listitem"><emph>Add:</emph> inserts a new item into the collection. Optionally a string value can be defined as the key to the item.</paragraph>
</listitem>
<listitem>
<paragraph id="par_id181633962000767" role="listitem"><emph>Count:</emph> returns the number of items in the collection.</paragraph>
</listitem>
<listitem>
<paragraph id="par_id521633962001072" role="listitem"><emph>Item:</emph> returns the item in the collection by passing its index or key.</paragraph>
</listitem>
<listitem>
<paragraph id="par_id981633962001272" role="listitem"><emph>Remove:</emph> removes the specified item from the collection by its index or key.</paragraph>
</listitem>
</list>
<note id="par_id221633976539661">Items in a Collection can be accessed either by their indices (as in a 1-based single-dimensional Array) or by their associated keys.</note>
<tip id="par_id811634214809970">The <link href="text/sbasic/shared/03/sf_dictionary.xhp"><literal>ScriptForge Dictionary</literal></link> service extends the <literal>Collection</literal> object by providing supplemental features as key retrieval and replacement, as well as import/export to Array objects and JSON strings.</tip>
<h2 id="hd_id51633962353863">Creating a Collection</h2>
<paragraph role="paragraph" id="par_id491633962366024">To create a <literal>Collection</literal> use the <literal>New</literal> keyword. The following example creates a <literal>Collection</literal> object and populates it with three items:</paragraph>
<bascode>
<paragraph role="bascode" localize="false" id="bas_id91633962500725">Dim myCollection as New Collection</paragraph>
<paragraph role="bascode" localize="false" id="bas_id31633962501246">myCollection.Add("Some text")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id71633962501432">myCollection.Add(100)</paragraph>
<paragraph role="bascode" localize="false" id="bas_id811633962501606">myCollection.Add(Array(1, 2, 3, 4))</paragraph>
<paragraph role="bascode" localize="false" id="bas_id351633962501979">MsgBox myCollection.Count ' 3</paragraph>
</bascode>
<h2 id="hd_id421633962742512">Adding Items</h2>
<bookmark xml-lang="en-US" localize="false" branch="index" id="bm_id591633974561425">
<bookmark_value>Collection;Add</bookmark_value>
</bookmark>
<paragraph role="paragraph" id="par_id261633962766238">The <literal>Add</literal> method can be used to add new items into the <literal>Collection</literal> object.</paragraph>
<embed href="text/sbasic/shared/00000003.xhp#functsyntax"/>
<paragraph role="paragraph" localize="false" id="par_id711633530276845">
<input>oCollection.Add(item, [key], [before|after])</input>
</paragraph>
<embed href="text/sbasic/shared/00000003.xhp#functparameters"/>
<paragraph id="par_id501633974650241" role="paragraph"><emph>item:</emph> the item to be added to the <literal>Collection</literal>. May be of any type.</paragraph>
<paragraph id="par_id181633974650705" role="paragraph"><emph>key:</emph> string value used as the unique key used to identify this value.</paragraph>
<paragraph id="par_id391633974651050" role="paragraph"><emph>before, after:</emph> optional keyword argument that indicates where the new item will be placed in the <literal>Collection</literal>. Only one of the arguments <literal>before</literal> or <literal>after</literal> can be specified to determine the index or key before which (or after which) the new item is to be placed.</paragraph>
<embed href="text/sbasic/shared/00000003.xhp#functexample"/>
<paragraph role="paragraph" id="par_id211633962988398">The example below adds two elements into a <literal>Collection</literal>. The first has a key associated with it, whereas the second does not.</paragraph>
<bascode>
<paragraph role="bascode" localize="false" id="bas_id231633963064060">Dim myCollection as New Collection</paragraph>
<paragraph role="bascode" localize="false" id="bas_id651633963064506">myCollection.Add(100, "first")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id241633963064748">myCollection.Add(101)</paragraph>
</bascode>
<paragraph role="paragraph" id="par_id71633963110632">The <literal>Add</literal> method also supports keyword arguments:</paragraph>
<bascode>
<paragraph role="bascode" localize="false" id="bas_id401633963141575">myCollection.Add(item := 100, key := "first")</paragraph>
</bascode>
<warning id="par_id941633963225913">Keys must be unique in a <literal>Collection</literal> object. Comparison between keys is <emph>case-insensitive</emph>. Adding duplicated keys will result in a runtime error.</warning>
<paragraph role="paragraph" id="par_id891633975568372">The example below illustrates how to use the <literal>Before</literal> and <literal>After</literal> keyword arguments to determine the position of the item that is being added.</paragraph>
<bascode>
<paragraph role="bascode" localize="false" id="bas_id641633975892167">Dim myCollection as Variant</paragraph>
<paragraph role="bascode" localize="false" id="bas_id971633975892478">myCollection = New Collection</paragraph>
<paragraph role="bascode" localize="false" id="bas_id971633975892702">myCollection.Add(item := 101, key := "first")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id351633975892870">myCollection.Add(item := 103, key := "third")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id851633975893071">myCollection.Add(item := 105, key := "fifth")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id771633975893271">MsgBox myCollection.Item(2) ' 103</paragraph>
<paragraph role="bascode" localize="false" id="bas_id331633975893495">myCollection.Add(item := 102, key := "second", before := "third")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id441633975893727">MsgBox myCollection.Item(2) ' 102</paragraph>
<paragraph role="bascode" localize="false" id="bas_id201633975961057">myCollection.Add(item := 104, key := "fourth", after := 3)</paragraph>
<paragraph role="bascode" localize="false" id="bas_id61633975961303">MsgBox myCollection.Item(4) ' 104</paragraph>
</bascode>
<note id="par_id121633976325472">Items in a <literal>Collection</literal> object are assigned an integer index value that starts at 1 and corresponds to the order in which they were added.</note>
<h2 id="hd_id141633977141797">Accessing Items</h2>
<bookmark xml-lang="en-US" localize="false" branch="index" id="bm_id481633977601834">
<bookmark_value>Collection;Item</bookmark_value>
</bookmark>
<paragraph role="paragraph" id="par_id431633977156315">Use the <literal>Item</literal> method to access a given item by its index or key.</paragraph>
<paragraph role="paragraph" localize="false" id="par_id371633977493008">
<input>oCollection.Item(index)</input>
</paragraph>
<paragraph role="paragraph" localize="false" id="par_id371633977493107">
<input>oCollection.Item(key)</input>
</paragraph>
<embed href="text/sbasic/shared/00000003.xhp#functparameters"/>
<paragraph role="paragraph" id="par_id261633976447187"><emph>index:</emph> an integer value specifying the index of the item to be returned.</paragraph>
<paragraph role="paragraph" id="par_id51633976782487"><emph>key:</emph> a string value specifying the key of the item to be returned.</paragraph>
<embed href="text/sbasic/shared/00000003.xhp#functexample"/>
<bascode>
<paragraph role="bascode" localize="false" id="bas_id671633977931198">Dim myCollection as New Collection</paragraph>
<paragraph role="bascode" localize="false" id="bas_id531633977931446">myCollection.Add(item := 101, key := "A")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id371633977931670">myCollection.Add(item := 102, key := "B")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id541633977931901">myCollection.Add(item := 103, key := "C")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id671633977932101">MsgBox myCollection.Item("A") ' 101</paragraph>
<paragraph role="bascode" localize="false" id="bas_id231633977932309">MsgBox myCollection.Item(3) ' 103</paragraph>
</bascode>
<h2 id="hd_id651633976030220">Removing Items</h2>
<bookmark xml-lang="en-US" localize="false" branch="index" id="bm_id311633977567197">
<bookmark_value>Collection;Remove</bookmark_value>
</bookmark>
<paragraph role="paragraph" id="par_id391633976125206">Use the <literal>Remove</literal> method to delete items from a <literal>Collection</literal> object.</paragraph>
<embed href="text/sbasic/shared/00000003.xhp#functsyntax"/>
<paragraph role="paragraph" id="par_id121633976268027">Items can be removed either by their indices or key values.</paragraph>
<paragraph role="paragraph" localize="false" id="par_id21633976180029">
<input>oCollection.Remove(index)</input>
</paragraph>
<paragraph role="paragraph" localize="false" id="par_id21633976180011">
<input>oCollection.Remove(key)</input>
</paragraph>
<embed href="text/sbasic/shared/00000003.xhp#functparameters"/>
<paragraph role="paragraph" id="par_id261633976447289"><emph>index:</emph> an integer value specifying the index of the item to be removed.</paragraph>
<paragraph role="paragraph" id="par_id51633976782455"><emph>key:</emph> a string value specifying the key of the item to be removed.</paragraph>
<embed href="text/sbasic/shared/00000003.xhp#functexample"/>
<bascode>
<paragraph role="bascode" localize="false" id="bas_id971633976850377">Dim myCollection as New Collection</paragraph>
<paragraph role="bascode" localize="false" id="bas_id941633976851194">myCollection.Add(item := 101, key := "first")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id111633976851408">myCollection.Add(item := 102, key := "second")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id231633976851633">myCollection.Add(item := 103, key := "third")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id151633976852777">MsgBox myCollection.Count ' 3</paragraph>
<paragraph role="bascode" localize="false" id="bas_id11633977022371">' Removes the first value</paragraph>
<paragraph role="bascode" localize="false" id="bas_id401633977022620">myCollection.Remove(1)</paragraph>
<paragraph role="bascode" localize="false" id="bas_id441633977022867">' Removes the value whose key is "third"</paragraph>
<paragraph role="bascode" localize="false" id="bas_id571633977023099">myCollection.Remove("third")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id221633977023371">MsgBox myCollection.Count ' 1</paragraph>
</bascode>
<h2 id="hd_id491633978085731">Iterating Over all Items</h2>
<paragraph role="paragraph" id="par_id91633978099143">It is possible to use a <literal>For Each ... Next</literal> statement to iterate over all items in a <literal>Collection</literal>.</paragraph>
<bascode>
<paragraph role="bascode" localize="false" id="bas_id671633977931167">Dim myCollection as New Collection</paragraph>
<paragraph role="bascode" localize="false" id="bas_id531633977931484">myCollection.Add(item := 101, key := "A")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id371633977931612">myCollection.Add(item := 102, key := "B")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id541633977931903">myCollection.Add(item := 103, key := "C")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id671633977932122">For Each value In myCollection</paragraph>
<paragraph role="bascode" localize="false" id="bas_id231633977932310"> MsgBox value</paragraph>
<paragraph role="bascode" localize="false" id="bas_id481633978297651">Next value</paragraph>
</bascode>
<h2 id="hd_id191634215349347">Clearing a Collection</h2>
<paragraph role="paragraph" id="par_id891634215363485">To remove all items from a <literal>Collection</literal> object call the <literal>Remove</literal> method for each item, as illustrated in the example below:</paragraph>
<bascode>
<paragraph role="bascode" id="bas_id681634215646028">' Create a sample Collection with two entries</paragraph>
<paragraph role="bascode" localize="false" id="bas_id291634215646265">Dim myCollection as New Collection</paragraph>
<paragraph role="bascode" localize="false" id="bas_id871634215646501">myCollection.Add(item := 10, key := "A")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id321634215646735">myCollection.Add(item := 11, key := "B")</paragraph>
<paragraph role="bascode" localize="false" id="bas_id261634215646972">MsgBox myCollection.Count ' 2</paragraph>
<paragraph role="bascode" id="bas_id391634215647196">' Removes all items in the collection</paragraph>
<paragraph role="bascode" localize="false" id="bas_id341634215647430">For i = myCollection.Count To 1 Step -1</paragraph>
<paragraph role="bascode" localize="false" id="bas_id651634215647648"> myCollection.Remove(i)</paragraph>
<paragraph role="bascode" localize="false" id="bas_id161634215647850">Next i</paragraph>
<paragraph role="bascode" localize="false" id="bas_id31634215648034">MsgBox myCollection.Count ' 0</paragraph>
</bascode>
<section id="relatedtopics">
<embed href="text/sbasic/shared/03104200.xhp#Array_h1"/>
<embed href="text/sbasic/shared/03/sf_dictionary.xhp#SFDictionary"/>
</section>
</body>
</helpdocument>
|
