Create a JavaScript program that can identify which number in a given array is different from the other two when two of the numbers in the array are equal

Question

Create a JavaScript program that can identify which number in a given array is different from the other two when two of the numbers in the array are equal

function checkThirdNumber() {
    let num1 = parseInt(document.querySelectorAll('.checkThirdInput')[0].value);
    let num2 = parseInt(document.querySelectorAll('.checkThirdInput')[1].value);
    let num3 = parseInt(document.querySelectorAll('.checkThirdInput')[2].value);
    document.getElementById('checkThirdResult').innerHTML = findThirdNumber([num1, num2, num3]);
  }
  function findThirdNumber(numbers) {
    let twoEquals = [];
    let oneUnequal = [];
    for (var i = 0; i < numbers.length; i++) {
      for (var j = i + 1; j < numbers.length; j++) {
        if (numbers[i] == numbers[j])  {
          twoEquals.push(numbers[i]);      
        }
        if (numbers[i] != numbers[j]) {
          oneUnequal.push(numbers[i]);
        }
      }
    }
    if ((twoEquals.length == 2) && (oneUnequal.length == 1)) {
      return 'The two equal numbers are: ' + twoEquals + '<br>' + 'The third number is: ' + oneUnequal;
    } else {
      return 'Numbers do not match.'
    }  
  }

<input type="number" class="checkThirdInput" value="3">
<input type="number" class="checkThirdInput" value="3">
<input type="number" class="checkThirdInput" value="4">
<button onclick="checkThirdNumber()">Check</button>
<div id="checkThirdResult"></div>

I attempted to resolve the issue using the code above, but for some reason it is not functioning correctly. The algorithm checks for two matching numbers and one different number in the input array, but there are some errors in the implementation.

javascript

Answer 1

Answer №1

function identifyThirdDuplicate(arr) {
let unique = [];
let duplicates = [];
for (var i = 0; i <= arr.length - 1; i++) {
    let isUnique = true;
    for (var j = i + 1; j <= arr.length; j++) {
        if (arr[i] === arr[j]) {
            duplicates.push(arr[i]);
            isUnique = false;
            break;
        }
    }
    if (isUnique && duplicates.indexOf(arr[i]) < 0) {
        unique.push(arr[i]);
    }
}
if (duplicates.length == 1) {
    return 'The duplicate is: ' + duplicates[0] + '<br>' + 'The third unique element: ' + unique[0];
} else {
    return 'No duplicate found.';
}

}

Answer 2

function identifyThirdDuplicate(arr) {
let unique = [];
let duplicates = [];
for (var i = 0; i <= arr.length - 1; i++) {
    let isUnique = true;
    for (var j = i + 1; j <= arr.length; j++) {
        if (arr[i] === arr[j]) {
            duplicates.push(arr[i]);
            isUnique = false;
            break;
        }
    }
    if (isUnique && duplicates.indexOf(arr[i]) < 0) {
        unique.push(arr[i]);
    }
}
if (duplicates.length == 1) {
    return 'The duplicate is: ' + duplicates[0] + '<br>' + 'The third unique element: ' + unique[0];
} else {
    return 'No duplicate found.';
}

}

Answer 3

Answer №2

You seem to be approaching this in a rather intricate manner.

Consider utilizing some predefined functions like map() and filter(). Additionally, instead of returning the htmlString from the function, you can directly assign it to the element's innerHTML.

Here is a suggested approach:

function findThird1() {
  let resultEl = document.getElementById('findThirdResult');
  let all = document.querySelectorAll('.findThirdInput');
  //retrieve all values
  let allValues = Array.from(all).map(el => el.value);
  //find the duplicates
  var two = allValues.filter((e, i, a) => a.indexOf(e) !== i);
  //find the unique value
  var one = allValues.filter(i => !two.includes(i));
  if (two.length && one.length) {
    resultEl.innerHTML =  'The duplicates are: ' + two + '<br>' + 'The unique value: ' + one;
  } else {
    resultEl.innerHTML = 'No duplicates found.'
  }  
}

<input type="number" class="findThirdInput" value="3">
<input type="number" class="findThirdInput" value="3">
<input type="number" class="findThirdInput" value="4">
<button onclick="findThird1()">Try</button>
<div id="findThirdResult"></div>

Answer 4

You seem to be approaching this in a rather intricate manner.

Consider utilizing some predefined functions like map() and filter(). Additionally, instead of returning the htmlString from the function, you can directly assign it to the element's innerHTML.

Here is a suggested approach:

function findThird1() {
  let resultEl = document.getElementById('findThirdResult');
  let all = document.querySelectorAll('.findThirdInput');
  //retrieve all values
  let allValues = Array.from(all).map(el => el.value);
  //find the duplicates
  var two = allValues.filter((e, i, a) => a.indexOf(e) !== i);
  //find the unique value
  var one = allValues.filter(i => !two.includes(i));
  if (two.length && one.length) {
    resultEl.innerHTML =  'The duplicates are: ' + two + '<br>' + 'The unique value: ' + one;
  } else {
    resultEl.innerHTML = 'No duplicates found.'
  }  
}

<input type="number" class="findThirdInput" value="3">
<input type="number" class="findThirdInput" value="3">
<input type="number" class="findThirdInput" value="4">
<button onclick="findThird1()">Try</button>
<div id="findThirdResult"></div>

Answer 5

Answer №3

Have you considered trying a solution like this?

function checkEquality1() {
  let num1 = parseInt(document.querySelectorAll('.checkEqualityInput')[0].value);
  let num2 = parseInt(document.querySelectorAll('.checkEqualityInput')[1].value);
  let num3 = parseInt(document.querySelectorAll('.checkEqualityInput')[2].value);
  document.getElementById('checkEqualityResult').innerHTML = checkEquality2([num1, num2, num3]);
}

function checkEquality2(arr) {
  let flag = false;
  for (var i = 0; i < arr.length - 1; i++) {
    if (arr[i] === arr[i + 1]) {
      flag = true;
      break;
    }
  }
  return flag ? 'Equals' : 'Not Equals';
}

Answer 6

Have you considered trying a solution like this?

function checkEquality1() {
  let num1 = parseInt(document.querySelectorAll('.checkEqualityInput')[0].value);
  let num2 = parseInt(document.querySelectorAll('.checkEqualityInput')[1].value);
  let num3 = parseInt(document.querySelectorAll('.checkEqualityInput')[2].value);
  document.getElementById('checkEqualityResult').innerHTML = checkEquality2([num1, num2, num3]);
}

function checkEquality2(arr) {
  let flag = false;
  for (var i = 0; i < arr.length - 1; i++) {
    if (arr[i] === arr[i + 1]) {
      flag = true;
      break;
    }
  }
  return flag ? 'Equals' : 'Not Equals';
}

Create a JavaScript program that can identify which number in a given array is different from the other two when two of the numbers in the array are equal

Answer №1

Answer №2

Answer №3

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