157 lines
3.1 KiB
Markdown
157 lines
3.1 KiB
Markdown
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<!--
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@license Apache-2.0
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Copyright (c) 2018 The Stdlib Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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-->
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# Deep Get
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> Get a nested property value.
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<section class="usage">
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## Usage
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```javascript
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var deepGet = require( '@stdlib/utils/deep-get' );
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```
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#### deepGet( obj, path\[, options] )
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Returns a nested property value.
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<!-- eslint-disable object-curly-newline, object-curly-spacing -->
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```javascript
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var obj = { 'a': { 'b': { 'c': 'd' } } };
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var val = deepGet( obj, 'a.b.c' );
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// returns 'd'
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```
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For `paths` including `arrays`, specify the numeric index.
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<!-- eslint-disable object-curly-newline, object-curly-spacing -->
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```javascript
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var arr = [
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{ 'a': [ {'x': 5} ] },
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{ 'a': [ {'x': 10} ] }
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];
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var val = deepGet( arr, '1.a.0.x' );
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// returns 10
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```
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The key `path` may be specified as either a delimited `string` or a key `array`.
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<!-- eslint-disable object-curly-newline, object-curly-spacing -->
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```javascript
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var obj = { 'a': { 'b': { 'c': 'd' } } };
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var val = deepGet( obj, [ 'a', 'b', 'c' ] );
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// returns 'd'
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```
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The function accepts the following `options`:
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- **sep**: key path separator. Default: `'.'`.
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By default, the function assumes `dot` separated key values. To specify an alternative separator, set the `sep` option.
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<!-- eslint-disable object-curly-newline, object-curly-spacing -->
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```javascript
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var obj = { 'a': { 'b': { 'c': 'd' } } };
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var val = deepGet( obj, 'a/b/c', {
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'sep': '/'
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});
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// returns 'd'
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```
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#### deepGet.factory( path\[, options] )
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Creates a reusable deep get function. The factory method ensures a `deepGet` function is configured identically by using the same set of provided `options`.
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```javascript
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var dget = deepGet.factory( 'a/b/c', {
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'sep': '/'
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});
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```
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#### dget( obj )
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Returns a nested property value.
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<!-- eslint-disable object-curly-newline, object-curly-spacing -->
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```javascript
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var dget = deepGet.factory( 'a.b.c' );
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var obj = { 'a': { 'b': { 'c': 'd' } } };
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var val = dget( obj );
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// returns 'd'
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```
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</section>
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<!-- /.usage -->
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<section class="examples">
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## Examples
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<!-- eslint no-undef: "error" -->
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```javascript
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var randu = require( '@stdlib/random/base/randu' );
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var deepGet = require( '@stdlib/utils/deep-get' );
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var data;
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var keys;
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var val;
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var i;
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data = new Array( 100 );
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for ( i = 0; i < data.length; i++ ) {
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data[ i ] = {
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'x': Date.now(),
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'y': [ randu(), randu(), i ]
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};
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}
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keys = [ 0, 'y', 2 ];
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for ( i = 0; i < data.length; i++ ) {
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keys[ 0 ] = i;
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val = deepGet( data, keys );
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console.log( val );
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}
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```
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</section>
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<!-- /.examples -->
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<section class="links">
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</section>
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<!-- /.links -->
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