144 lines
3.1 KiB
Markdown
144 lines
3.1 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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# isEnumerableProperty
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> Test if an object's own property is enumerable.
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<section class="usage">
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## Usage
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```javascript
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var isEnumerableProperty = require( '@stdlib/assert/is-enumerable-property' );
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```
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#### isEnumerableProperty( value, property )
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Returns a `boolean` indicating if a `value` has an enumerable `property`.
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```javascript
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var value = {
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'beep': 'boop'
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};
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var bool = isEnumerableProperty( value, 'beep' );
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// returns true
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bool = isEnumerableProperty( value, 'constructor' );
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// returns false
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```
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</section>
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<!-- /.usage -->
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<section class="notes">
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## Notes
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- In contrast to the native [Object.prototype.propertyIsEnumerable][mdn-object-property-is-enumerable], this function does **not** throw when provided `null` or `undefined`. Instead, the function returns `false`.
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```javascript
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var bool = isEnumerableProperty( null, 'a' );
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// returns false
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bool = isEnumerableProperty( void 0, 'a' );
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// returns false
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```
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- Value arguments other than `null` or `undefined` are coerced to `objects`.
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```javascript
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var bool = isEnumerableProperty( 'beep', '1' );
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// returns true
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```
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- Property arguments are coerced to `strings`.
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```javascript
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var value = {
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'null': false
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};
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var bool = isEnumerableProperty( value, null );
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// returns true
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value = {
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'[object Object]': false
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};
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bool = isEnumerableProperty( value, {} );
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// returns true
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```
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</section>
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<!-- /.notes -->
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<section class="examples">
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## Examples
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<!-- eslint-disable object-curly-newline -->
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<!-- eslint no-undef: "error" -->
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```javascript
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var isEnumerableProperty = require( '@stdlib/assert/is-enumerable-property' );
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var bool = isEnumerableProperty( { 'a': 'b' }, 'a' );
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// returns true
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bool = isEnumerableProperty( [ 'a' ], 0 );
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// returns true
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bool = isEnumerableProperty( [ 'a' ], 'length' );
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// returns false
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bool = isEnumerableProperty( {}, 'toString' );
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// returns false
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bool = isEnumerableProperty( {}, 'hasOwnProperty' );
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// returns false
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bool = isEnumerableProperty( null, 'a' );
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// returns false
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bool = isEnumerableProperty( void 0, 'a' );
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// returns false
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bool = isEnumerableProperty( { 'null': false }, null );
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// returns true
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bool = isEnumerableProperty( { '[object Object]': false }, {} );
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// returns true
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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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[mdn-object-property-is-enumerable]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/propertyIsEnumerable
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</section>
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<!-- /.links -->
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