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Expression
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<h4 class="name" id="Expression">
<a href="#Expression" class="doc-link"></a>
new Cesium.Expression<span class="signature">(<span class="optional">expression</span>, <span class="optional">defines</span>)</span>
<div class="source-link rightLinks">
<a href="https://github.com/CesiumGS/cesium/blob/1.91/Source/Scene/Expression.js#L37">Scene/Expression.js 37</a>
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<div class="description">
An expression for a style applied to a <a href="Cesium3DTileset.html"><code>Cesium3DTileset</code></a>.
<p>
Evaluates an expression defined using the
<a href="https://github.com/CesiumGS/3d-tiles/tree/main/specification/Styling">3D Tiles Styling language</a>.
</p>
<p>
Implements the <a href="StyleExpression.html"><code>StyleExpression</code></a> interface.
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<table class="params">
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th class="last">Description</th>
</tr>
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<td class="name"><code>expression</code></td>
<td class="type">
<span class="param-type">String</span>
</td>
<td class="description last">
<span class="optional">optional</span>
The expression defined using the 3D Tiles Styling language.</td>
</tr>
<tr>
<td class="name"><code>defines</code></td>
<td class="type">
<span class="param-type">Object</span>
</td>
<td class="description last">
<span class="optional">optional</span>
Defines in the style.</td>
</tr>
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<dl class="details">
<h5>Examples:</h5>
<pre><code class="language-javascript">const expression = new Cesium.Expression('(regExp("^Chest").test(${County})) &amp;&amp; (${YearBuilt} >= 1970)');
expression.evaluate(feature); // returns true or false depending on the feature's properties</code></pre>
<pre><code class="language-javascript">const expression = new Cesium.Expression('(${Temperature} > 90) ? color("red") : color("white")');
expression.evaluateColor(feature, result); // returns a Cesium.Color object</code></pre>
</dl>
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<h3 class="subsection-title">Members</h3>
<div class="nameContainer">
<h4 class="name" id="expression">
<a href="#expression" class="doc-link"></a>
<span class="type-signature attribute-readonly">readonly</span> expression<span class="type-signature"> : String</span>
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<a href="https://github.com/CesiumGS/cesium/blob/1.91/Source/Scene/Expression.js#L71">Scene/Expression.js 71</a>
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<div class="description">
Gets the expression defined in the 3D Tiles Styling language.
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<dl class="details">
<span class="details-header">Default Value:</span>
<code class="language-javascript">undefined</code>
</dl>
<h3 class="subsection-title">Methods</h3>
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<h4 class="name" id="evaluate">
<a href="#evaluate" class="doc-link"></a>
evaluate<span class="signature">(feature, <span class="optional">result</span>)</span> &rarr; <span class="type-signature returnType">Boolean|Number|String|RegExp|<a href="Cartesian2.html">Cartesian2</a>|<a href="Cartesian3.html">Cartesian3</a>|<a href="Cartesian4.html">Cartesian4</a>|<a href="Color.html">Color</a></span>
<div class="source-link rightLinks">
<a href="https://github.com/CesiumGS/cesium/blob/1.91/Source/Scene/Expression.js#L137">Scene/Expression.js 137</a>
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</h4>
</div>
<div class="description">
Evaluates the result of an expression, optionally using the provided feature's properties. If the result of
the expression in the
<a href="https://github.com/CesiumGS/3d-tiles/tree/main/specification/Styling">3D Tiles Styling language</a>
is of type <code>Boolean</code>, <code>Number</code>, or <code>String</code>, the corresponding JavaScript
primitive type will be returned. If the result is a <code>RegExp</code>, a Javascript <code>RegExp</code>
object will be returned. If the result is a <code>Cartesian2</code>, <code>Cartesian3</code>, or <code>Cartesian4</code>,
a <a href="Cartesian2.html"><code>Cartesian2</code></a>, <a href="Cartesian3.html"><code>Cartesian3</code></a>, or <a href="Cartesian4.html"><code>Cartesian4</code></a> object will be returned. If the <code>result</code> argument is
a <a href="Color.html"><code>Color</code></a>, the <a href="Cartesian4.html"><code>Cartesian4</code></a> value is converted to a <a href="Color.html"><code>Color</code></a> and then returned.
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<table class="params">
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<th>Name</th>
<th>Type</th>
<th class="last">Description</th>
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<td class="name"><code>feature</code></td>
<td class="type">
<span class="param-type"><a href="Cesium3DTileFeature.html">Cesium3DTileFeature</a></span>
</td>
<td class="description last">
The feature whose properties may be used as variables in the expression.</td>
</tr>
<tr>
<td class="name"><code>result</code></td>
<td class="type">
<span class="param-type">Object</span>
</td>
<td class="description last">
<span class="optional">optional</span>
The object onto which to store the result.</td>
</tr>
</tbody>
</table>
<h5>Returns:</h5>
<div class="param-desc">
The result of evaluating the expression.
</div>
<dl class="details">
</dl>
<div class="nameContainer">
<h4 class="name" id="evaluateColor">
<a href="#evaluateColor" class="doc-link"></a>
evaluateColor<span class="signature">(feature, <span class="optional">result</span>)</span> &rarr; <span class="type-signature returnType"><a href="Color.html">Color</a></span>
<div class="source-link rightLinks">
<a href="https://github.com/CesiumGS/cesium/blob/1.91/Source/Scene/Expression.js#L163">Scene/Expression.js 163</a>
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</h4>
</div>
<div class="description">
Evaluates the result of a Color expression, optionally using the provided feature's properties.
<p>
This is equivalent to <a href="Expression.html#evaluate"><code>Expression#evaluate</code></a> but always returns a <a href="Color.html"><code>Color</code></a> object.
</p>
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<table class="params">
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<th>Name</th>
<th>Type</th>
<th class="last">Description</th>
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<tbody>
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<td class="name"><code>feature</code></td>
<td class="type">
<span class="param-type"><a href="Cesium3DTileFeature.html">Cesium3DTileFeature</a></span>
</td>
<td class="description last">
The feature whose properties may be used as variables in the expression.</td>
</tr>
<tr>
<td class="name"><code>result</code></td>
<td class="type">
<span class="param-type"><a href="Color.html">Color</a></span>
</td>
<td class="description last">
<span class="optional">optional</span>
The object in which to store the result</td>
</tr>
</tbody>
</table>
<h5>Returns:</h5>
<div class="param-desc">
The modified result parameter or a new Color instance if one was not provided.
</div>
<dl class="details">
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