<p>A <a href="https://ponyfill.com">ponyfill</a> for <code>Buffer.from</code>, uses native implementation if available.</p>

<h3>Installation</h3>

<pre><code>
npm install --save buffer-from
</code></pre>

<h3>Usage</h3>

<pre><code>
const bufferFrom = require('buffer-from')

console.log(bufferFrom([1, 2, 3, 4]))
//=> <Buffer 01 02 03 04>

const arr = new Uint8Array([1, 2, 3, 4])
console.log(bufferFrom(arr.buffer, 1, 2))
//=> <Buffer 02 03>

console.log(bufferFrom('test', 'utf8'))
//=> <Buffer 74 65 73 74>

const buf = bufferFrom('test')
console.log(bufferFrom(buf))
//=> <Buffer 74 65 73 74>
</code></pre>

<h3>API</h3>

<h4>bufferFrom(array)</h4>

<ul>
<li><code>array</code> &lt;Array&gt;</li>
</ul>

<p>Allocates a new <code>Buffer</code> using an <code>array</code> of octets.</p>

<h4>bufferFrom(arrayBuffer[, byteOffset[, length]])</h4>

<ul>
<li><code>arrayBuffer</code> &lt;ArrayBuffer&gt; The <code>.buffer</code> property of a TypedArray or ArrayBuffer</li>
<li><code>byteOffset</code> &lt;Integer&gt; Where to start copying from <code>arrayBuffer</code>. <strong>Default:</strong> <code>0</code></li>
<li><code>length</code> &lt;Integer&gt; How many bytes to copy from <code>arrayBuffer</code>. <strong>Default:</strong> <code>arrayBuffer.length - byteOffset</code></li>
</ul>

<p>When passed a reference to the <code>.buffer</code> property of a TypedArray instance, the</p>
<p>newly created <code>Buffer</code> will share the same allocated memory as the TypedArray.</p>

<p>The optional <code>byteOffset</code> and <code>length</code> arguments specify a memory range within</p>
<p>the <code>arrayBuffer</code> that will be shared by the <code>Buffer</code>.</p>

<h4>bufferFrom(buffer)</h4>

<ul>
<li><code>buffer</code> &lt;Buffer&gt; An existing <code>Buffer</code> to copy data from</li>
</ul>

<p>Copies the passed <code>buffer</code> data onto a new <code>Buffer</code> instance.</p>

<h4>bufferFrom(string[, encoding])</h4>

<ul>
<li><code>string</code> &lt;String&gt; A string to encode.</li>
<li><code>encoding</code> &lt;String&gt; The encoding of <code>string</code>. <strong>Default:</strong> <code>'utf8'</code></li>
</ul>

<p>Creates a new <code>Buffer</code> containing the given JavaScript string <code>string</code>. If</p>
<p>provided, the <code>encoding</code> parameter identifies the character encoding of</p>
<p><code>string</code>.</p>

<h3>See also</h3>

<ul>
<li><a href="https://github.com/LinusU/buffer-alloc">buffer-alloc</a> A ponyfill for <code>Buffer.alloc</code></li>
<li><a href="https://github.com/LinusU/buffer-alloc-unsafe">buffer-alloc-unsafe</a> A ponyfill for <code>Buffer.allocUnsafe</code></li>
</ul>

<hr>

<p>本文由模极社发布</p>

<hr>
<p>!<a href="upload://cTUm8tHLABMewfCKi5BBEMzPd5E.svg">Buffer From</a></p>

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