52 lines
2.3 KiB
Markdown
52 lines
2.3 KiB
Markdown
---
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title: How can I remove trailing zeros from a number in JavaScript?
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shortTitle: Remove trailing zeros from number
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type: story
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language: javascript
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tags: [math]
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author: chalarangelo
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cover: island-corridor
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excerpt: When formatting decimal values in JavaScript, trailing zeros can be undesired. Here's how to deal with them.
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dateModified: 2022-05-08T05:00:00-04:00
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---
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JavaScript provides a couple of ways to format numeric values to a given precision. Namely, you can use `Number.prototype.toFixed()` and `Number.prototype.toPrecision()` to similar effect. However, neither of them deals with trailing zeros in the decimal part. Here's a few ways you can remove them:
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### Regular expression
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Provided that the number is converted to a fixed-point string, you can use a regular expression to remove trailing zeros. All you have to do is match the decimal point (`\.`) and replace any zeros after it (`0+`) until the end of the string (`$`).
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```js
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const toFixedWithoutZeros = (num, precision) =>
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num.toFixed(precision).replace(/\.0+$/, '');
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toFixedWithoutZeros(1.001, 2); // '1'
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toFixedWithoutZeros(1.500, 2); // '1.50'
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```
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The main issue with this approach is that the regular expression will only remove trailing zeros if the decimal part has no other digits before them. Writing a regular expression to remove trailing zeros from any number is a bit more involved and gets harder to read. Thus, this approach is discouraged.
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### Multiply by 1
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A better way to remove trailing zeros is to multiply by `1`. This method will remove trailing zeros from the decimal part of the number, accounting for non-zero digits after the decimal point. The only downside is that the result is a numeric value, so it has to be converted back to a string.
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```js
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const toFixedWithoutZeros = (num, precision) =>
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`${1 * num.toFixed(precision)}`;
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toFixedWithoutZeros(1.001, 2); // '1'
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toFixedWithoutZeros(1.500, 2); // '1.5'
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```
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### Number.parseFloat
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Similar to the previous approach, you can use `Number.parseFloat()` to remove trailing zeros from a number. This method also accounts for non-zero digits after the decimal point. We recommend this approach as it's the most readable.
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```js
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const toFixedWithoutZeros = (num, precision) =>
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`${Number.parseFloat(num.toFixed(precision))}`;
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toFixedWithoutZeros(1.001, 2); // '1'
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toFixedWithoutZeros(1.500, 2); // '1.5'
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```
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