1<?xml version="1.0" encoding="UTF-8"?> 2 3<!--*********************************************************** 4 * 5 * Licensed to the Apache Software Foundation (ASF) under one 6 * or more contributor license agreements. See the NOTICE file 7 * distributed with this work for additional information 8 * regarding copyright ownership. The ASF licenses this file 9 * to you under the Apache License, Version 2.0 (the 10 * "License"); you may not use this file except in compliance 11 * with the License. You may obtain a copy of the License at 12 * 13 * http://www.apache.org/licenses/LICENSE-2.0 14 * 15 * Unless required by applicable law or agreed to in writing, 16 * software distributed under the License is distributed on an 17 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 18 * KIND, either express or implied. See the License for the 19 * specific language governing permissions and limitations 20 * under the License. 21 * 22 ***********************************************************--> 23 24<helpdocument version="1.0"> 25<meta> 26<topic id="textsbasicshared03102600xml" indexer="include"> 27<title id="tit" xml-lang="en-US">IsNull Function [Runtime]</title> 28<filename>/text/sbasic/shared/03102600.xhp</filename> 29</topic> 30</meta> 31<body> 32<section id="isnull"> 33<bookmark xml-lang="en-US" branch="index" id="bm_id3155555"> 34<bookmark_value>IsNull function</bookmark_value> 35<bookmark_value>Null value</bookmark_value> 36</bookmark> 37<paragraph role="heading" id="hd_id3155555" xml-lang="en-US" level="1" l10n="U" oldref="1"><link href="text/sbasic/shared/03102600.xhp" name="IsNull Function [Runtime]">IsNull Function [Runtime]</link></paragraph> 38<paragraph role="paragraph" id="par_id3146957" xml-lang="en-US" l10n="U" oldref="2">Tests if a Variant contains the special Null value, indicating that the variable does not contain data.</paragraph> 39</section> 40<paragraph role="heading" id="hd_id3150670" xml-lang="en-US" level="2" l10n="U" oldref="3">Syntax:</paragraph> 41<paragraph role="paragraph" id="par_id3150984" xml-lang="en-US" l10n="U" oldref="4">IsNull (Var)</paragraph> 42<paragraph role="heading" id="hd_id3149514" xml-lang="en-US" level="2" l10n="U" oldref="5">Return value:</paragraph> 43<paragraph role="paragraph" id="par_id3145609" xml-lang="en-US" l10n="U" oldref="6">Bool</paragraph> 44<paragraph role="heading" id="hd_id3149669" xml-lang="en-US" level="2" l10n="U" oldref="7">Parameters:</paragraph> 45<paragraph role="paragraph" id="par_id3159414" xml-lang="en-US" l10n="U" oldref="8"> 46<emph>Var:</emph> Any variable that you want to test. This function returns True if the Variant contains the Null value, or False if the Variant does not contain the Null value.</paragraph> 47<paragraph role="paragraph" id="par_idN1062A" xml-lang="en-US" l10n="NEW"> 48<emph>Null</emph> - This value is used for a variant data sub type without valid contents.</paragraph> 49<embed href="text/sbasic/shared/00000003.xhp#errorcode"/> 50<embed href="text/sbasic/shared/00000003.xhp#err5"/> 51<paragraph role="heading" id="hd_id3153381" xml-lang="en-US" level="2" l10n="U" oldref="9">Example:</paragraph> 52<paragraph role="paragraph" id="par_id3154140" xml-lang="en-US" l10n="U" oldref="10">Sub ExampleIsNull</paragraph> 53<paragraph role="paragraph" id="par_id3145172" xml-lang="en-US" l10n="U" oldref="11">Dim vVar As Variant</paragraph> 54<paragraph role="paragraph" id="par_id3144760" xml-lang="en-US" l10n="U" oldref="12">msgbox IsNull(vVar)</paragraph> 55<paragraph role="paragraph" id="par_id3153970" xml-lang="en-US" l10n="U" oldref="13">end sub</paragraph> 56</body> 57</helpdocument> 58