README.md (2027B)
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 # isInteger 22 23 > Test if a finite [double-precision floating-point number][ieee754] is an integer. 24 25 <section class="usage"> 26 27 ## Usage 28 29 ```javascript 30 var isInteger = require( '@stdlib/math/base/assert/is-integer' ); 31 ``` 32 33 #### isInteger( x ) 34 35 Tests if a finite [double-precision floating-point number][ieee754] is an `integer`. 36 37 ```javascript 38 var bool = isInteger( 1.0 ); 39 // returns true 40 ``` 41 42 </section> 43 44 <!-- /.usage --> 45 46 <section class="notes"> 47 48 ## Notes 49 50 - The function assumes a **finite** `number`. If provided positive or negative `infinity`, the function will return `true`, when, in fact, the result is undefined. If `x` can be `infinite`, wrap the implementation as follows: 51 52 ```javascript 53 function check( x ) { 54 return ( 55 x < Infinity && 56 x > -Infinity && 57 isInteger( x ) 58 ); 59 } 60 61 var bool = check( Infinity ); 62 // returns false 63 64 bool = check( -Infinity ); 65 // returns false 66 ``` 67 68 </section> 69 70 <!-- /.notes --> 71 72 <section class="examples"> 73 74 ## Examples 75 76 <!-- eslint no-undef: "error" --> 77 78 ```javascript 79 var isInteger = require( '@stdlib/math/base/assert/is-integer' ); 80 81 var bool = isInteger( -5.0 ); 82 // returns true 83 84 bool = isInteger( 3.14 ); 85 // returns false 86 87 bool = isInteger( NaN ); 88 // returns false 89 ``` 90 91 </section> 92 93 <!-- /.examples --> 94 95 <section class="links"> 96 97 [ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985 98 99 </section> 100 101 <!-- /.links -->