npm package: @stdlib/regexp-decimal-number
Description: Return a regular expression to match a decimal number.
Author: The Stdlib Authors
Latest version: 0.2.3

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# reDecimalNumber

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> [Regular expression][mdn-regexp] to match a decimal number.

<section class="installation">

## Installation

```bash
npm install @stdlib/regexp-decimal-number
```

</section>

<section class="usage">

## Usage

```javascript
var reDecimalNumber = require( '@stdlib/regexp-decimal-number' );
```

#### reDecimalNumber( \[options] )

Returns a [regular expression][mdn-regexp] to match a decimal number.

```javascript
var RE_DECIMAL_NUMBER = reDecimalNumber();

var out = RE_DECIMAL_NUMBER.test( 'foo 1.234.' );
// returns true

out = RE_DECIMAL_NUMBER.test( '2:3' );
// returns false
```

The function accepts an `options` object with optional properties:

-   **flags**: `string` specifying regular expression [flags][mdn-regexp-flags]. Default: `''`.
-   **capture**: `boolean` indicating whether to create a capture group for the match. Default: `false`.

By default, the function returns a regular expression which does not have any flags specified. To specify [flags][mdn-regexp-flags], set the `flags` option with a list of flags (which may be in any order).

```javascript
var replace = require( '@stdlib/string-replace' );

var RE_DECIMAL_NUMBER = reDecimalNumber({
    'flags': 'g'
});

var str = 'beep 1.234 boop 1.234';
var out = replace( str, RE_DECIMAL_NUMBER, '' );
// returns 'beep  boop '
```

By default, the function returns a regular expression which does not capture the part of a string matching the regular expression. To capture matches, set the `capture` option.

```javascript
var RE_DECIMAL_NUMBER = reDecimalNumber({
    'capture': true
});

var out = RE_DECIMAL_NUMBER.exec( 'beep 1.234 boop' ).slice();
// returns [ '1.234', '1.234' ]

out = RE_DECIMAL_NUMBER.exec( '' );
// returns null
```

#### reDecimalNumber.REGEXP

[Regular expression][mdn-regexp] to match a decimal number.

```javascript
var bool = reDecimalNumber.REGEXP.test( '2:3' );
// returns false
```

#### reDecimalNumber.REGEXP_CAPTURE

[Regular expression][mdn-regexp] to capture characters matching a decimal number.

```javascript
var parts = reDecimalNumber.REGEXP_CAPTURE.exec( '1.234' );
// returns [ '1.234', '1.234' ]
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   A leading digit is not required.

    ```javascript
    var bool = reDecimalNumber.REGEXP.test( '.5' );
    // returns true
    ```

-   A decimal point and at least one trailing digit is required.

    ```javascript
    var bool = reDecimalNumber.REGEXP.test( '5.' );
    // returns false
    ```

-   The `REGEXP` regular expression is defined as

    ```text
    /[-+]{0,1}[0-9]*\.[0-9]+/
    ```

-   The `REGEXP_CAPTURE` regular expression is defined as

    ```text
    /([-+]{0,1}[0-9]*\.[0-9]+)/
    ```

</section>

<!-- /.notes -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var reDecimalNumber = require( '@stdlib/regexp-decimal-number' );

var RE_DECIMAL_NUMBER = reDecimalNumber();

var bool = RE_DECIMAL_NUMBER.test( '1.234' );
// returns true

bool = RE_DECIMAL_NUMBER.test( 'beep 1.234' );
// returns true

bool = RE_DECIMAL_NUMBER.test( '1.234 boop' );
// returns true

bool = RE_DECIMAL_NUMBER.test( 'foo 1.234.' );
// returns true

bool = RE_DECIMAL_NUMBER.test( 'foo 1.234.567.890' );
// returns true

bool = RE_DECIMAL_NUMBER.test( '1.234!' );
// returns true

bool = RE_DECIMAL_NUMBER.test( '0.234' );
// returns true

bool = RE_DECIMAL_NUMBER.test( '.234' );
// returns true

bool = RE_DECIMAL_NUMBER.test( 'beep .234' );
// returns true

bool = RE_DECIMAL_NUMBER.test( '.234 boop' );
// returns true

bool = RE_DECIMAL_NUMBER.test( '1.0' );
// returns true

bool = RE_DECIMAL_NUMBER.test( '-1.0' );
// returns true

bool = RE_DECIMAL_NUMBER.test( '+1.0' );
// returns true

bool = RE_DECIMAL_NUMBER.test( '0.0' );
// returns true

bool = RE_DECIMAL_NUMBER.test( '.0' );
// returns true

bool = RE_DECIMAL_NUMBER.test( '1.234:' );
// returns true

bool = RE_DECIMAL_NUMBER.test( '1.234%' );
// returns true

bool = RE_DECIMAL_NUMBER.test( '0' );
// returns false

bool = RE_DECIMAL_NUMBER.test( 'beep 0' );
// returns false

bool = RE_DECIMAL_NUMBER.test( '2:3' );
// returns false

bool = RE_DECIMAL_NUMBER.test( 'beep' );
// returns false

bool = RE_DECIMAL_NUMBER.test( '' );
// returns false
```

</section>

<!-- /.examples -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

</section>

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<section class="main-repo" >

* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

</section>

<!-- /.stdlib -->

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[npm-url]: https://npmjs.org/package/@stdlib/regexp-decimal-number

[test-image]: https://github.com/stdlib-js/regexp-decimal-number/actions/workflows/test.yml/badge.svg?branch=v0.2.3
[test-url]: https://github.com/stdlib-js/regexp-decimal-number/actions/workflows/test.yml?query=branch:v0.2.3

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/regexp-decimal-number/main.svg
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[stdlib]: https://github.com/stdlib-js/stdlib

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[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

[deno-url]: https://github.com/stdlib-js/regexp-decimal-number/tree/deno
[deno-readme]: https://github.com/stdlib-js/regexp-decimal-number/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/regexp-decimal-number/tree/umd
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[esm-url]: https://github.com/stdlib-js/regexp-decimal-number/tree/esm
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[branches-url]: https://github.com/stdlib-js/regexp-decimal-number/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/regexp-decimal-number/main/LICENSE

[mdn-regexp]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions

[mdn-regexp-flags]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions#advanced_searching_with_flags_2

</section>

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