QueryingLINQtoJSON.aml

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<topic id="QueryingLINQtoJSON" revisionNumber="1">
  <developerConceptualDocument xmlns="http://ddue.schemas.microsoft.com/authoring/2003/5" xmlns:xlink="http://www.w3.org/1999/xlink">
    <introduction>
      <para>LINQ to JSON provides a number of methods for getting data from its objects. The index methods on JObject/JArray let you quickly get data by its property name
      on an object or index in a collection, while <codeEntityReference>M:Newtonsoft.Json.Linq.JToken.Children</codeEntityReference> lets you get ranges
      of data as <codeInline>IEnumerable&lt;JToken&gt;</codeInline> to then query using LINQ.</para>
    </introduction>
    
    <section>
      <title>Getting values by Property Name or Collection Index</title>
      <content>
        <!-- Uncomment this to create a sub-section outline
        <autoOutline /> -->
        <para>The simplest way to get a value from LINQ to JSON is to use the
        <codeEntityReference>P:Newtonsoft.Json.Linq.JToken.Item(System.Object)</codeEntityReference> index on
        JObject/JArray and then cast the returned <codeEntityReference>T:Newtonsoft.Json.Linq.JValue</codeEntityReference> to the type you want.
        </para>

<code lang="cs" source="..\Src\Newtonsoft.Json.Tests\Documentation\LinqToJsonTests.cs" region="LinqToJsonSimpleQuerying" title="Getting JSON Values" />

      </content>
    </section>
    <section>
      <title>Querying with LINQ</title>
      <content>
        <para>JObject/JArray can also be queried using LINQ. <codeEntityReference>M:Newtonsoft.Json.Linq.JToken.Children</codeEntityReference>
        returns the children values of a JObject/JArray
		as an <codeInline>IEnumerable&lt;JToken&gt;</codeInline> that can then be queried with the standard Where/OrderBy/Select LINQ operators.</para>
        
<alert class="note">
        <para><codeEntityReference>M:Newtonsoft.Json.Linq.JToken.Children</codeEntityReference> returns all the children of a token. If it is a
        JObject it will return a collection of properties to work with, and if
        it is a JArray you will get a collection of the array's values.</para>
</alert>

<code lang="cs" source="..\Src\Newtonsoft.Json.Tests\Documentation\LinqToJsonTests.cs" region="LinqToJsonQuerying" title="Querying JSON" />

        <para>LINQ to JSON can also be used to manually convert JSON to a .NET object.</para>

<code lang="cs" source="..\Src\Newtonsoft.Json.Tests\Documentation\LinqToJsonTests.cs" region="LinqToJsonDeserializeObject" title="Deserializing Using LINQ Objects" />

        <para>Manually serializing and deserializing between .NET objects is useful when you are
        working with JSON that doesn't closely match your .NET objects.</para>

<code lang="cs" source="..\Src\Newtonsoft.Json.Tests\Documentation\LinqToJsonTests.cs" region="LinqToJsonDeserializeExample" title="Deserializing Using LINQ Example" />
      </content>
    </section>
    <relatedTopics>
      <link xlink:href="LINQtoJSON" />

      <codeEntityReference>P:Newtonsoft.Json.Linq.JToken.Item(System.Object)</codeEntityReference>
      <codeEntityReference>M:Newtonsoft.Json.Linq.JToken.Children</codeEntityReference>
    </relatedTopics>
  </developerConceptualDocument>
</topic>