div2.js (1573B)
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 floor = require( '@stdlib/math/base/special/floor' ); 24 25 26 // VARIABLES // 27 28 var NBITS = 32; 29 30 31 // MAIN // 32 33 /** 34 * Converts a nonnegative integer to a literal bit representation using the divide-by-2 algorithm. 35 * 36 * @private 37 * @param {NonNegativeInteger} x - nonnegative integer 38 * @returns {BinaryString} bit representation 39 * 40 * @example 41 * var v = div2( 3 ); 42 * // returns '11' 43 * 44 * @example 45 * var v = div2( 0 ); 46 * // returns '' 47 * 48 * @example 49 * var v = div2( 12 ); 50 * // returns '1100' 51 * 52 * @example 53 * var v = div2( 188 ); 54 * // returns '10111100' 55 */ 56 function div2( x ) { 57 var str = ''; 58 var i; 59 var y; 60 61 // We repeatedly divide by 2 and check for a remainder. If a remainder exists, the number is odd and we add a '1' bit... 62 i = NBITS; 63 while ( x > 0 && i ) { 64 y = x / 2; 65 x = floor( y ); 66 if ( y === x ) { 67 str = '0' + str; 68 } else { 69 str = '1' + str; 70 } 71 i -= 1; 72 } 73 return str; 74 } 75 76 77 // EXPORTS // 78 79 module.exports = div2;