# C1.LiveLinq.Indexing.IndexCollection-1.Find

## Content

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<h1 id="C1_LiveLinq_Indexing_IndexCollection_1_Find_" data-uid="C1.LiveLinq.Indexing.IndexCollection`1.Find*">Find Method
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<div class="markdown level0 summary"></div>
<div class="markdown level0 conceptual"></div>



<a id="C1_LiveLinq_Indexing_IndexCollection_1_Find_" data-uid="C1.LiveLinq.Indexing.IndexCollection`1.Find*"></a>
<h4 id="C1_LiveLinq_Indexing_IndexCollection_1_Find_System_Linq_Expressions_LambdaExpression_" data-uid="C1.LiveLinq.Indexing.IndexCollection`1.Find(System.Linq.Expressions.LambdaExpression)">Find(LambdaExpression)</h4>
<div class="markdown level1 summary"><p>Finds an index in the collection by its key selector.</p>
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<div class="markdown level1 conceptual"></div>
<h5 class="declaration">Declaration</h5>
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  <pre><code class="lang-csharp hljs">public Index&lt;T&gt; Find(LambdaExpression keySelector)</code></pre>
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  <pre><code class="lang-vbnet hljs">Public Function Find(keySelector As LambdaExpression) As Index(Of T)</code></pre>
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<h5 class="parameters">Parameters</h5>
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      <th>Type</th>
      <th>Name</th>
      <th>Description</th>
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      <td><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.linq.expressions.lambdaexpression">LambdaExpression</a></td>
      <td><span class="parametername">keySelector</span></td>
      <td><p>Key selector expression of an index, see <a class="xref" href="C1.LiveLinq.Indexing.IndexDefinition-1.KeySelector.html#C1_LiveLinq_Indexing_IndexDefinition_1_KeySelector">KeySelector</a>.</p>
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<h5 class="returns">Returns</h5>
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      <th>Type</th>
      <th>Description</th>
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      <td><a class="xref" href="C1.LiveLinq.Indexing.Index-1.html">Index</a>&lt;T&gt;</td>
      <td><p>An index with the given key selector, if it is found; otherwise, <b>null</b>.</p>
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<a id="C1_LiveLinq_Indexing_IndexCollection_1_Find_" data-uid="C1.LiveLinq.Indexing.IndexCollection`1.Find*"></a>
<h4 id="C1_LiveLinq_Indexing_IndexCollection_1_Find__1_System_Linq_Expressions_Expression_System_Func__0___0___" data-uid="C1.LiveLinq.Indexing.IndexCollection`1.Find``1(System.Linq.Expressions.Expression{System.Func{`0,``0}})">Find&lt;TKey&gt;(Expression&lt;Func&lt;T, TKey&gt;&gt;)</h4>
<div class="markdown level1 summary"><p>Finds an index in the collection by its key selector.</p>
</div>
<div class="markdown level1 conceptual"></div>
<h5 class="declaration">Declaration</h5>
<div class="codewrapper">
  <pre><code class="lang-csharp hljs">public Index&lt;T, TKey&gt; Find&lt;TKey&gt;(Expression&lt;Func&lt;T, TKey&gt;&gt; keySelector)</code></pre>
</div>
<div class="codewrapper">
  <pre><code class="lang-vbnet hljs">Public Function Find(Of TKey)(keySelector As Expression(Of Func(Of T, TKey))) As Index(Of T, TKey)</code></pre>
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<h5 class="parameters">Parameters</h5>
<table class="table table-bordered table-condensed">
  <thead>
    <tr>
      <th>Type</th>
      <th>Name</th>
      <th>Description</th>
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      <td><a class="xref" href="https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1">Expression</a>&lt;<a class="xref" href="https://learn.microsoft.com/dotnet/api/system.func-2">Func</a>&lt;T, TKey&gt;&gt;</td>
      <td><span class="parametername">keySelector</span></td>
      <td><p>Key selector expression of an index, see <a class="xref" href="C1.LiveLinq.Indexing.IndexDefinition-1.KeySelector.html#C1_LiveLinq_Indexing_IndexDefinition_1_KeySelector">KeySelector</a>.</p>
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  </tbody>
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<h5 class="returns">Returns</h5>
<table class="table table-bordered table-condensed">
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
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  </thead>
  <tbody>
    <tr>
      <td><a class="xref" href="C1.LiveLinq.Indexing.Index-2.html">Index</a>&lt;T, TKey&gt;</td>
      <td><p>An index with the given key selector, if it is found; otherwise, <b>null</b>.</p>
</td>
    </tr>
  </tbody>
</table>
<h5 class="typeParameters">Type Parameters</h5>
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      <th>Name</th>
      <th>Description</th>
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      <td><span class="parametername">TKey</span></td>
      <td><p>The type of the index key.</p>
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