npm package: @stdlib/string-base-format-interpolate
Description: Generate string from a token array by interpolating values.
Author: The Stdlib Authors
Latest version: 0.2.4

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  <summary>
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# formatInterpolate

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

> Generate string from a token array by interpolating values.

<section class="intro">

</section>

<!-- /.intro -->

<section class="installation">

## Installation

```bash
npm install @stdlib/string-base-format-interpolate
```

</section>

<section class="usage">

## Usage

```javascript
var formatInterpolate = require( '@stdlib/string-base-format-interpolate' );
```

#### formatInterpolate( tokens, ...args )

Generates string from a token array by interpolating values.

```javascript
var formatTokenize = require( '@stdlib/string-base-format-tokenize' );

var str = 'Hello, %s! My name is %s.';
var tokens = formatTokenize( str );
var out = formatInterpolate( tokens, 'World', 'Bob' );
// returns 'Hello, World! My name is Bob.'
```

The array of `tokens` should contain string parts and format identifier objects.

```javascript
var tokens = [ 'beep ', { 'specifier': 's' } ];
var out = formatInterpolate( tokens, 'boop' );
// returns 'beep boop'
```

Format identifier objects can have the following properties:

| property  | description                                                                                         |
| --------- | --------------------------------------------------------------------------------------------------- |
| specifier | format specifier (one of 's', 'c', 'd', 'i', 'u', 'b', 'o', 'x', 'X', 'e', 'E', 'f', 'F', 'g', 'G') |
| flags     | format flags (string with any of '0', ' ', '+', '-', '#')                                           |
| width     | minimum field width (integer or `'*'`)                                                              |
| precision | precision (integer or `'*'`)                                                                        |
| mapping   | positional mapping from format specifier to argument index                                          |

</section>

<!-- /.usage -->

<section class="examples">

## Examples

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

```javascript
var formatTokenize = require( '@stdlib/string-base-format-tokenize' );
var PI = require( '@stdlib/constants-float64-pi' );
var formatInterpolate = require( '@stdlib/string-base-format-interpolate' );

var tokens = formatTokenize( 'Hello %s!' );
var out = formatInterpolate( tokens, 'World' );
// returns 'Hello World!'

tokens = formatTokenize( 'Pi: ~%.2f' );
out = formatInterpolate( tokens, PI );
// returns 'Pi: ~3.14'

tokens = formatTokenize( 'Index: %d, Value: %s' );
out = formatInterpolate( tokens, 0, 'foo' );
// returns 'Index: 0, Value: foo'
```

</section>

<!-- /.examples -->

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

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/string-base/format-tokenize`][@stdlib/string/base/format-tokenize]</span><span class="delimiter">: </span><span class="description">tokenize a string into an array of string parts and format identifier objects.</span>

</section>

<!-- /.related -->

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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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[umd]: https://github.com/umdjs/umd
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<!-- <related-links> -->

[@stdlib/string/base/format-tokenize]: https://www.npmjs.com/package/@stdlib/string-base-format-tokenize

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</section>

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