ethers.js/docs/v5/api/utils/display-logic/index.html
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<div class="breadcrumbs"><a href="/v5/">Documentation</a>&nbsp;&nbsp;&raquo;&nbsp;&nbsp;<a href="/v5/api/">API</a>&nbsp;&nbsp;&raquo;&nbsp;&nbsp;<a href="/v5/api/utils/">Utilities</a>&nbsp;&nbsp;&raquo;&nbsp;&nbsp;<span class="current">Display Logic and Input</span></div>
<a name="display-logic-and-input"></a><h1 class="show-anchors"><div>Display Logic and Input<div class="anchors"><a class="self" href="/v5/api/utils/display-logic/#display-logic-and-input"></a></div></div></h1><p>When creating an Application, it is useful to convert between user-friendly strings (usually displaying <b>ether</b>) and the machine-readable values that contracts and maths depend on (usually in <b>wei</b>).</p>
<p>For example, a Wallet may specify the balance in ether, and gas prices in gwei for the User Interface, but when sending a transaction, both must be specified in wei.</p>
<p>The <a href="/v5/api/utils/display-logic/#unit-conversion">parseUnits</a> will parse a string representing ether, such as <code class="inline">1.1</code> into a <a href="/v5/api/utils/bignumber/">BigNumber</a> in wei, and is useful when a user types in a value, such as sending 1.1 ether.</p>
<p>The <a href="/v5/api/utils/display-logic/#unit-conversion">formatUnits</a> will format a <a href="/v5/api/utils/bignumber/#BigNumberish">BigNumberish</a> into a string, which is useful when displaying a balance.</p>
<a name="display-logic-and-input--units"></a><h2 class="show-anchors"><div>Units<div class="anchors"><a class="self" href="/v5/api/utils/display-logic/#display-logic-and-input--units"></a></div></div></h2>
<a name="display-logic-and-input--units--decimal-count"></a><h3 class="show-anchors"><div>Decimal Count<div class="anchors"><a class="self" href="/v5/api/utils/display-logic/#display-logic-and-input--units--decimal-count"></a></div></div></h3><p>A <b>Unit</b> can be specified as an number, which indicates the number of decimal places that should be used.</p>
<p><b>Examples:</b></p>
<p><ul><li>1 ether in wei, has <b>18</b> decimal places (i.e. 1 ether represents 10<sup>18</sup> wei) </li><li>1 bitcoin in Satoshi, has <b>8</b> decimal places (i.e. 1 bitcoin represents 10<sup>8</sup> satoshi) </li></ul></p>
<a name="display-logic-and-input--units--named-units"></a><h3 class="show-anchors"><div>Named Units<div class="anchors"><a class="self" href="/v5/api/utils/display-logic/#display-logic-and-input--units--named-units"></a></div></div></h3><p>There are also several common <b>Named Units</b>, in which case their name (as a string) may be used.</p>
<table class="table compact"><tr><td align="center" width="50%"><b>Name</b></td><td align="center" width="50%"><b>Decimals</b></td><td class="fix">&nbsp;</td></tr><tr><td align="center" width="50%"><i>wei</i></td><td align="center" width="50%">0</td><td class="fix">&nbsp;</td></tr><tr><td align="center" width="50%"><i>kwei</i></td><td align="center" width="50%">3</td><td class="fix">&nbsp;</td></tr><tr><td align="center" width="50%"><i>mwei</i></td><td align="center" width="50%">6</td><td class="fix">&nbsp;</td></tr><tr><td align="center" width="50%"><i>gwei</i></td><td align="center" width="50%">9</td><td class="fix">&nbsp;</td></tr><tr><td align="center" width="50%"><i>szabo</i></td><td align="center" width="50%">12</td><td class="fix">&nbsp;</td></tr><tr><td align="center" width="50%"><i>finney</i></td><td align="center" width="50%">15</td><td class="fix">&nbsp;</td></tr><tr><td align="center" width="50%"><i>ether</i></td><td align="center" width="50%">18</td><td class="fix">&nbsp;</td></tr></table><a name="display-logic-and-input--functions"></a><h2 class="show-anchors"><div>Functions<div class="anchors"><a class="self" href="/v5/api/utils/display-logic/#display-logic-and-input--functions"></a></div></div></h2>
<a name="display-logic-and-input--functions--formatting"></a><h3 class="show-anchors"><div>Formatting<div class="anchors"><a class="self" href="/v5/api/utils/display-logic/#display-logic-and-input--functions--formatting"></a></div></div></h3>
<a name="utils-commify"></a><div class="property show-anchors"><div class="signature"><span class="path">ethers</span><span class="symbol">.</span><span class="path">utils</span><span class="symbol">.</span><span class="method">commify</span><span class="symbol">(</span> <span class="param">value</span> <span class="symbol">)</span> <span class="arrow">&rArr;</span> <span class="returns">string</span><div class="anchors"><a class="self" href="/v5/api/utils/display-logic/#utils-commify"></a><a class="source" href="https://github.com/ethers-io/ethers.js/blob/ethers-v5-beta/packages/units/src.ts/index.ts#L23">source</a></div></div><div class="body"><p>Returns a string with value grouped by 3 digits, separated by <code class="inline">,</code>.</p>
</div></div><a name="unit-conversion"></a><a name="display-logic-and-input--functions--unit-conversion"></a><h3 class="show-anchors"><div>Conversion<div class="anchors"><a class="self" href="/v5/api/utils/display-logic/#unit-conversion"></a></div></div></h3>
<a name="utils-formatUnits"></a><div class="property show-anchors"><div class="signature"><span class="path">ethers</span><span class="symbol">.</span><span class="path">utils</span><span class="symbol">.</span><span class="method">formatUnits</span><span class="symbol">(</span> <span class="param">value</span> <span class="symbol">[</span> <span class="symbol">,</span> <span class="param">unit</span> = "<span class="param">ether</span>" <span class="symbol">]</span> <span class="symbol">)</span> <span class="arrow">&rArr;</span> <span class="returns">string</span><div class="anchors"><a class="self" href="/v5/api/utils/display-logic/#utils-formatUnits"></a><a class="source" href="https://github.com/ethers-io/ethers.js/blob/ethers-v5-beta/packages/units/src.ts/index.ts#L61">source</a></div></div><div class="body"><p>Returns a string representation of <i>value</i> formatted with <i>unit</i> digits (if it is a number) or to the unit specified (if a string).</p>
</div></div><a name="utils-formatEther"></a><div class="property show-anchors"><div class="signature"><span class="path">ethers</span><span class="symbol">.</span><span class="path">utils</span><span class="symbol">.</span><span class="method">formatEther</span><span class="symbol">(</span> <span class="param">value</span> <span class="symbol">)</span> <span class="arrow">&rArr;</span> <span class="returns">string</span><div class="anchors"><a class="self" href="/v5/api/utils/display-logic/#utils-formatEther"></a><a class="source" href="https://github.com/ethers-io/ethers.js/blob/ethers-v5-beta/packages/units/src.ts/index.ts#L77">source</a></div></div><div class="body"><p>The equivalent to calling <code class="inline">formatUnits(value, "ether")</code>.</p>
</div></div><a name="utils-parseUnits"></a><div class="property show-anchors"><div class="signature"><span class="path">ethers</span><span class="symbol">.</span><span class="path">utils</span><span class="symbol">.</span><span class="method">parseUnits</span><span class="symbol">(</span> <span class="param">value</span> <span class="symbol">[</span> <span class="symbol">,</span> <span class="param">unit</span> = "<span class="param">ether</span>" <span class="symbol">]</span> <span class="symbol">)</span> <span class="arrow">&rArr;</span> <span class="returns"><a href="/v5/api/utils/bignumber/">BigNumber</a></span><div class="anchors"><a class="self" href="/v5/api/utils/display-logic/#utils-parseUnits"></a><a class="source" href="https://github.com/ethers-io/ethers.js/blob/ethers-v5-beta/packages/units/src.ts/index.ts#L69">source</a></div></div><div class="body"><p>Returns a <a href="/v5/api/utils/bignumber/">BigNumber</a> representation of <i>value</i>, parsed with <i>unit</i> digits (if it is a number) or from the unit specified (if a string).</p>
</div></div><a name="utils-parseEther"></a><div class="property show-anchors"><div class="signature"><span class="path">ethers</span><span class="symbol">.</span><span class="path">utils</span><span class="symbol">.</span><span class="method">parseEther</span><span class="symbol">(</span> <span class="param">value</span> <span class="symbol">)</span> <span class="arrow">&rArr;</span> <span class="returns"><a href="/v5/api/utils/bignumber/">BigNumber</a></span><div class="anchors"><a class="self" href="/v5/api/utils/display-logic/#utils-parseEther"></a><a class="source" href="https://github.com/ethers-io/ethers.js/blob/ethers-v5-beta/packages/units/src.ts/index.ts#L81">source</a></div></div><div class="body"><p>The equivalent to calling <code class="inline">parseUnits(value, "ether")</code>.</p>
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