@stdlib/string/base/code-point-at/README.md

String manipulation functions.

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# codePointAt

> Return a Unicode [code point][code-point] from a string at a specified position.

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## Usage

```javascript
var codePointAt = require( '@stdlib/string/base/code-point-at' );
```

#### codePointAt( string, position, backward )

Returns a Unicode [code point][code-point] from a string at a specified position.

```javascript
var out = codePointAt( 'last man standing', 4, false );
// returns 32
```

The function supports a `backward` argument for performing backward iteration for low surrogates.

```javascript
var out = codePointAt( '🌷', 1, true );
// returns 127799
```

The function supports providing a negative `position`.

```javascript
var out = codePointAt( 'last man standing', -13, false );
// returns 32
```

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## Notes

This function differs from [`String.prototype.codePointAt`][mdn-string-codepointat] in the following ways:

-   The function supports providing a negative `position`. If provided a negative `position`, the function determines the string position relative to the end of the string.
-   The function supports a `backward` argument for performing backward iteration for low surrogates. [`String.prototype.codePointAt`][mdn-string-codepointat] simply returns the low surrogate value if no [UTF-16][utf-16] surrogate pair begins at the specified position. If invoked with `backward` set to `true`, this function will return the code point after aggregating with the preceding high surrogate, if the specified position does not mark the start of a surrogate pair.

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## Examples

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```javascript
var codePointAt = require( '@stdlib/string/base/code-point-at' );

var v = codePointAt( 'last man standing', 4, false );
// returns 32

v = codePointAt( 'presidential election', 8, true );
// returns 116

v = codePointAt( 'अनुच्छेद', 2, false );
// returns 2369

v = codePointAt( '🌷', 1, true );
// returns 127799
```

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[code-point]: https://en.wikipedia.org/wiki/Code_point

[mdn-string-codepointat]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/codePointAt

[utf-16]: https://en.wikipedia.org/wiki/UTF-16

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