<!-- @license Apache-2.0 Copyright (c) 2018 The Stdlib Authors. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. --> # isNumber > Test if a value is a number. <section class="usage"> ## Usage ```javascript var isNumber = require( '@stdlib/assert/is-number' ); ``` #### isNumber( value ) Tests if a `value` is a `number`. <!-- eslint-disable no-new-wrappers --> ```javascript var Number = require( '@stdlib/number/ctor' ); var bool = isNumber( 3.14 ); // returns true bool = isNumber( new Number( 3.14 ) ); // returns true bool = isNumber( NaN ); // returns true bool = isNumber( null ); // returns false ``` #### isNumber.isPrimitive( value ) Tests if a `value` is a primitive `number`. <!-- eslint-disable no-new-wrappers --> ```javascript var Number = require( '@stdlib/number/ctor' ); var bool = isNumber.isPrimitive( 3.14 ); // returns true bool = isNumber.isPrimitive( NaN ); // returns true bool = isNumber.isPrimitive( new Number( 3.14 ) ); // returns false ``` #### isNumber.isObject( value ) Tests if a `value` is a `Number` object. <!-- eslint-disable no-new-wrappers --> ```javascript var Number = require( '@stdlib/number/ctor' ); var bool = isNumber.isObject( 3.14 ); // returns false bool = isNumber.isObject( new Number( 3.14 ) ); // returns true ``` </section> <!-- /.usage --> <section class="examples"> ## Examples <!-- eslint-disable no-new-wrappers --> <!-- eslint no-undef: "error" --> ```javascript var Number = require( '@stdlib/number/ctor' ); var isNumber = require( '@stdlib/assert/is-number' ); var bool = isNumber( 5 ); // returns true bool = isNumber( new Number( 5 ) ); // returns true bool = isNumber( NaN ); // returns true bool = isNumber( '5' ); // returns false bool = isNumber( null ); // returns false ``` </section> <!-- /.examples --> <section class="links"> </section> <!-- /.links -->