time-to-botec

Benchmark sampling in different programming languages
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README.md (3159B)

      1 <!--
      2 
      3 @license Apache-2.0
      4 
      5 Copyright (c) 2018 The Stdlib Authors.
      6 
      7 Licensed under the Apache License, Version 2.0 (the "License");
      8 you may not use this file except in compliance with the License.
      9 You may obtain a copy of the License at
     10 
     11    http://www.apache.org/licenses/LICENSE-2.0
     12 
     13 Unless required by applicable law or agreed to in writing, software
     14 distributed under the License is distributed on an "AS IS" BASIS,
     15 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     16 See the License for the specific language governing permissions and
     17 limitations under the License.
     18 
     19 -->
     20 
     21 # isEnumerableProperty
     22 
     23 > Test if an object's own property is enumerable.
     24 
     25 <section class="usage">
     26 
     27 ## Usage
     28 
     29 ```javascript
     30 var isEnumerableProperty = require( '@stdlib/assert/is-enumerable-property' );
     31 ```
     32 
     33 #### isEnumerableProperty( value, property )
     34 
     35 Returns a `boolean` indicating if a `value` has an enumerable `property`.
     36 
     37 ```javascript
     38 var value = {
     39     'beep': 'boop'
     40 };
     41 
     42 var bool = isEnumerableProperty( value, 'beep' );
     43 // returns true
     44 
     45 bool = isEnumerableProperty( value, 'constructor' );
     46 // returns false
     47 ```
     48 
     49 </section>
     50 
     51 <!-- /.usage -->
     52 
     53 <section class="notes">
     54 
     55 ## Notes
     56 
     57 -   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`.
     58 
     59     ```javascript
     60     var bool = isEnumerableProperty( null, 'a' );
     61     // returns false
     62 
     63     bool = isEnumerableProperty( void 0, 'a' );
     64     // returns false
     65     ```
     66 
     67 -   Value arguments other than `null` or `undefined` are coerced to `objects`.
     68 
     69     ```javascript
     70     var bool = isEnumerableProperty( 'beep', '1' );
     71     // returns true
     72     ```
     73 
     74 -   Property arguments are coerced to `strings`.
     75 
     76     ```javascript
     77     var value = {
     78         'null': false
     79     };
     80     var bool = isEnumerableProperty( value, null );
     81     // returns true
     82 
     83     value = {
     84         '[object Object]': false
     85     };
     86     bool = isEnumerableProperty( value, {} );
     87     // returns true
     88     ```
     89 
     90 </section>
     91 
     92 <!-- /.notes -->
     93 
     94 <section class="examples">
     95 
     96 ## Examples
     97 
     98 <!-- eslint-disable object-curly-newline -->
     99 
    100 <!-- eslint no-undef: "error" -->
    101 
    102 ```javascript
    103 var isEnumerableProperty = require( '@stdlib/assert/is-enumerable-property' );
    104 
    105 var bool = isEnumerableProperty( { 'a': 'b' }, 'a' );
    106 // returns true
    107 
    108 bool = isEnumerableProperty( [ 'a' ], 0 );
    109 // returns true
    110 
    111 bool = isEnumerableProperty( [ 'a' ], 'length' );
    112 // returns false
    113 
    114 bool = isEnumerableProperty( {}, 'toString' );
    115 // returns false
    116 
    117 bool = isEnumerableProperty( {}, 'hasOwnProperty' );
    118 // returns false
    119 
    120 bool = isEnumerableProperty( null, 'a' );
    121 // returns false
    122 
    123 bool = isEnumerableProperty( void 0, 'a' );
    124 // returns false
    125 
    126 bool = isEnumerableProperty( { 'null': false }, null );
    127 // returns true
    128 
    129 bool = isEnumerableProperty( { '[object Object]': false }, {} );
    130 // returns true
    131 ```
    132 
    133 </section>
    134 
    135 <!-- /.examples -->
    136 
    137 <section class="links">
    138 
    139 [mdn-object-property-is-enumerable]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/propertyIsEnumerable
    140 
    141 </section>
    142 
    143 <!-- /.links -->