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diff --git a/files/zh-cn/web/javascript/reference/global_objects/dataview/getfloat64/index.html b/files/zh-cn/web/javascript/reference/global_objects/dataview/getfloat64/index.html new file mode 100644 index 0000000000..885acb9421 --- /dev/null +++ b/files/zh-cn/web/javascript/reference/global_objects/dataview/getfloat64/index.html @@ -0,0 +1,91 @@ +--- +title: DataView.prototype.getFloat64() +slug: Web/JavaScript/Reference/Global_Objects/DataView/getFloat64 +translation_of: Web/JavaScript/Reference/Global_Objects/DataView/getFloat64 +--- +<div>{{JSRef}}</div> + +<p><strong><code>getFloat64()</code></strong><code>方法</code><code>从</code><a href="https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/DataView" title="DataView 视图提供了一种用于向 ArrayBuffer 读写数据的底层接口。"><code>DataView</code></a>相对于起始位置偏移 n 个字节处开始,获取一个64-bit数(双精度浮点型,8个字节).</p> + +<div>{{EmbedInteractiveExample("pages/js/dataview-getfloat64.html")}}</div> + + + +<h2 id="语法">语法</h2> + +<pre class="syntaxbox"><var>dataview</var>.getFloat64(byteOffset [, littleEndian])</pre> + +<h3 id="参数">参数</h3> + +<dl> + <dt>byteOffset</dt> + <dd>偏移量, 单位为字节, 从头开始计算.</dd> + <dt>littleEndian</dt> + <dd>{{optional_inline}} Indicates whether the 64-bit float is stored in {{Glossary("Endianness", "little- or big-endian")}} format. If false or undefined, a big-endian value is read.</dd> +</dl> + +<h3 id="返回">返回</h3> + +<dl> + <dd>一个双精度浮点型64位数.</dd> +</dl> + +<h3 id="抛出错误">抛出错误</h3> + +<dl> + <dt>{{jsxref("RangeError")}}</dt> + <dd>如果byteOffset超出了视图能储存的值,就会抛出错误.</dd> +</dl> + +<h2 id="描述">描述</h2> + +<dl> + <dd>没有对齐约束; 多字节值可以从任何偏移量获取.</dd> +</dl> + +<h2 id="例子">例子</h2> + +<pre class="brush:js">var buffer = new ArrayBuffer(8); +var dataview = new DataView(buffer); +dataview.getFloat64(1); // 0 +</pre> + +<h2 id="规范">规范</h2> + +<table class="standard-table"> + <tbody> + <tr> + <th scope="col">Specification</th> + <th scope="col">Status</th> + <th scope="col">Comment</th> + </tr> + <tr> + <td>{{SpecName('Typed Array')}}</td> + <td>{{Spec2('Typed Array')}}</td> + <td>Superseded by ECMAScript 6.</td> + </tr> + <tr> + <td>{{SpecName('ES6', '#sec-dataview.prototype.getfloat64', 'DataView.prototype.getFloat64')}}</td> + <td>{{Spec2('ES6')}}</td> + <td>Initial definition in ECMA standard.</td> + </tr> + <tr> + <td>{{SpecName('ESDraft', '#sec-dataview.prototype.getfloat64', 'DataView.prototype.getFloat64')}}</td> + <td>{{Spec2('ESDraft')}}</td> + <td></td> + </tr> + </tbody> +</table> + +<h2 id="浏览器支持">浏览器支持</h2> + + + +<p>{{Compat("javascript.builtins.DataView.getFloat64")}}</p> + +<h2 id="另见">另见</h2> + +<ul> + <li>{{jsxref("DataView")}}</li> + <li>{{jsxref("ArrayBuffer")}}</li> +</ul> |