TheAlgorithms · raklaptudirm · Oct 20, 2021 · Oct 14, 2021
@@ -1,4 +1,4 @@
-import {IsPowerOfTwo} from '../IsPowerOfTwo'
+import { IsPowerOfTwo } from '../IsPowerOfTwo'
 
 test('Check if 0 is a power of 2 or not:', () => {
   const res = IsPowerOfTwo(0)

@@ -0,0 +1,59 @@
+const pad = (num, padlen) => {
+  var pad = new Array(1 + padlen).join(0)
+  return (pad + num).slice(-pad.length)
+}
+
+const hexLookup = (bin) => {
+  let binary = bin
+  if (binary.length < 4) {
+    binary = pad(binary, 4)
+  }
+  switch (binary) {
+    case '0000': return '0'
+    case '0001': return '1'
+    case '0010': return '2'
+    case '0011': return '3'
+    case '0100': return '4'
+    case '0101': return '5'
+    case '0110': return '6'
+    case '0111': return '7'
+    case '1000': return '8'
+    case '1001': return '9'
+    case '1010': return 'A'
+    case '1011': return 'B'
+    case '1100': return 'C'
+    case '1101': return 'D'
+    case '1110': return 'E'
+    case '1111': return 'F'
+  }
+}
+const binaryToHex = (binaryString) => {
+  /*
+  Function for convertung Binary to Hex
+
+  1. The conversion will start from Least Significant Digit (LSB) to the Most Significant Bit (MSB).
+  2. We divide the bits into sections of 4-bits starting from LSB to MSB.
+  3. If the MSB get less than 4 bits, then we pad 0s to the front of it.
+
+  For Example:
+  Binary String = '1001101'
+
+  1. Divide it to 2 parts => ['100', '1101']
+  2. Pad 0s the MSB so it'll be => ['0100', '1101']
+  3. Use the lookup table and merge them, therefore the result is 4D.
+
+  */
+
+  let result = ''
+  binaryString = binaryString.split('')
+  for (let i = binaryString.length - 1; i >= 0; i = i - 4) {
+    if (i >= 3) {
+      result += hexLookup(binaryString.slice(i - 3, i + 1).join(''))
+    } else {
+      result += hexLookup(binaryString.slice(0, i + 1).join(''))
+    }
+  }
+  return result.split('').reverse().join('')
+}
+
+export default binaryToHex
@@ -40,8 +40,7 @@ const fahrenheitToRankine = (fahrenheit) => {
 const kelvinToCelsius = (kelvin) => {
   // Wikipedia reference: https://en.wikipedia.org/wiki/Kelvin
   // Wikipedia reference: https://en.wikipedia.org/wiki/Celsius
-  return Math.round((kelvin) - 273.15)
-
+  return Math.round((kelvin) - 273.15)
 }
 
 const kelvinToFahrenheit = (kelvin) => {
@@ -53,7 +52,7 @@ const kelvinToFahrenheit = (kelvin) => {
 const kelvinToRankine = (kelvin) => {
   // Wikipedia reference: https://en.wikipedia.org/wiki/Kelvin
   // Wikipedia reference: https://en.wikipedia.org/wiki/Rankine_scale
-  return Math.round(( (kelvin) * 9 / 5))
+  return Math.round(((kelvin) * 9 / 5))
 }
 
 const rankineToCelsius = (rankine) => {

@@ -0,0 +1,19 @@
+import binaryToHex from '../BinaryToHex'
+
+describe('BinaryToHex', () => {
+  it('expects to return correct hexadecimal value', () => {
+    expect(binaryToHex('1000')).toBe('8')
+  })
+
+  it('expects to return correct hexadecimal value for more than one hex digit', () => {
+    expect(binaryToHex('11101010')).toBe('EA')
+  })
+
+  it('expects to return correct hexadecimal value for padding-required binary', () => {
+    expect(binaryToHex('1001101')).toBe('4D')
+  })
+
+  it('expects to return correct hexadecimal value, matching (num).toString(16)', () => {
+    expect(binaryToHex('1111')).toBe(parseInt('1111', 2).toString(16).toUpperCase())
+  })
+})