bubble-sort-algorithm.js

//test cases
let tests = [
  {
    input: 3,
    result: 'Please input an array of integers.'
  },
  {
    input: '[]',
    result: 'Please input an array of integers.'
  },
  {
    input: [],
    result: 'Please input an array of integers.'
  },
  {
    input: [3, 9, 5, 1, 8],
    result: [1, 3, 5, 8, 9]
  },
  {
    input: [3, -9, 5, 1, -8],
    result: [-9, -8, 1, 3, 5]
  },
  {
    input: [0, -9, 0, 1, -8],
    result: [-9, -8, 0, 0, 1]
  },
  {
    input: [0, -9, '0', 1, '-8'],
    result: 'Please input an array of integers.'
  },
]

// puts the array through a round of rearranging elements
function nextRound(input) {
  let arrayCopy = input

  for (let i = 0; i < arrayCopy.length - 1; i++) {
    let firstNo = arrayCopy[i]
    let secondNo = arrayCopy[i + 1]

    // if current number > next number, swap each other
    if (firstNo > secondNo) {
      arrayCopy[i + 1] = firstNo
      arrayCopy[i] = secondNo
    }
    // else, leave them be
  }

  // return arranged array
  return arrayCopy
}

// checks if the array elements are in ascending order
function needAnotherRound(input) {
  for (let i = 0; i < input.length - 1; i++) {
    let firstNo = input[i]
    let secondNo = input[i + 1]

    // if current number > next number, return true
    if (firstNo > secondNo) {
      return true
      // else move to next number in array
    } else {
      continue
    }
  }
}

// validate input array elements
function isIntegerArray (input) {
  // if an array
  if (Array.isArray(input)) {
    // if empty array
    if (input.length < 1) return false

    // iterate through each element and return false if one of them happens to be not an integer
    for (let i = 0; i < input.length; i++) {
      if (Number.isInteger(input[i])) continue
      else return false
    }
    return true
  // if not an array
  } else return false
}

function bubbleSort(input) {
  if (isIntegerArray(input)) {
    let sortedArray = input
  
    while (1) {
      if (needAnotherRound(sortedArray)) {
        sortedArray = nextRound(sortedArray)
        continue
      } else {
        return sortedArray
      }
    }
  } else return 'Please input an array of integers.'
}

// test
for (let i = 0; i < tests.length; i++) {
  let pass = false
  let result = bubbleSort(tests[i].input)
  let expectedResult = tests[i].result

  if (JSON.stringify(result) === JSON.stringify(expectedResult)) pass = true

  console.log(`input ${i} - ${pass ? 'pass' : 'fail'}`)
}