133 lines
2.7 KiB
Markdown
133 lines
2.7 KiB
Markdown
<!--
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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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# pick
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> Return a partial object copy containing only specified keys.
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<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
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<section class="intro">
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</section>
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<!-- /.intro -->
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<!-- Package usage documentation. -->
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<section class="usage">
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## Usage
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```javascript
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var pick = require( '@stdlib/utils/pick' );
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```
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#### pick( obj, keys )
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Returns a partial copy of an `object`. The returned `object` contains only specified `keys`.
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```javascript
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var obj1 = {
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'a': 1,
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'b': 2,
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'c': 3
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};
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var obj2 = pick( obj1, 'b' );
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// returns { 'b': 2 }
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var obj3 = pick( obj1, [ 'b', 'c' ] );
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// returns { 'b': 2, 'c': 3 }
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```
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If a key does not exist as an **own** property in a source `object`, the key is ignored.
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```javascript
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var obj1 = {
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'a': 1,
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'b': 2,
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'c': 3
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};
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var obj2 = pick( obj1, 'd' );
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// returns {}
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```
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</section>
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<!-- /.usage -->
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<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
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<section class="notes">
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## Notes
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- The function returns a **shallow** copy.
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- The function **only** copies **own** properties. Hence, the function never copies inherited properties.
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</section>
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<!-- /.notes -->
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<!-- Package usage examples. -->
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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 pick = require( '@stdlib/utils/pick' );
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var obj1 = {
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'a': 1,
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'b': 2,
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'c': 3,
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'd': 4,
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'e': 5
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};
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var obj2 = pick( obj1, [ 'b', 'c', 'e' ] );
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// returns { 'b': 2, 'c': 3, 'e': 5 }
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```
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</section>
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<!-- /.examples -->
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<!-- Section to include cited references. If references are included, add a horizontal rule *before* the section. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
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<section class="references">
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</section>
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<!-- /.references -->
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<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
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<section class="links">
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</section>
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<!-- /.links -->
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