main.js (1456B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2018 The Stdlib Authors. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 'use strict'; 20 21 // MODULES // 22 23 var lowercase = require( '@stdlib/string/lowercase' ); 24 var uppercase = require( '@stdlib/string/uppercase' ); 25 var isString = require( './../../is-string' ).isPrimitive; 26 27 28 // MAIN // 29 30 /** 31 * Tests if a value is a lowercase string. 32 * 33 * @param {*} value - value to test 34 * @returns {boolean} boolean indicating whether value is a lowercase string 35 * 36 * @example 37 * var bool = isLowercase( 'salt and light' ); 38 * // returns true 39 * 40 * @example 41 * var bool = isLowercase( 'HELLO' ); 42 * // returns false 43 * 44 * @example 45 * var bool = isLowercase( 'World' ); 46 * // returns false 47 * 48 * @example 49 * var bool = isLowercase( '!' ); 50 * // returns false 51 */ 52 function isLowercase( value ) { 53 return ( 54 isString( value ) && 55 value === lowercase( value ) && 56 value !== uppercase( value ) 57 ); 58 } 59 60 61 // EXPORTS // 62 63 module.exports = isLowercase;