Discovering duplicates in an array list with Angular 6 by using the 'some' method

Question

Discovering duplicates in an array list with Angular 6 by using the 'some' method

Greetings! I am currently working with an array of values, as shown below:

    var users = [{
        name: 'John',
        email: '<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="93f9fcfbfde0fcfdd3fef2faffbdf0fcfe">[email protected]</a>',
        age: 25,
    },
    {
        name: 'Tom',
        email: '<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="0f7b60624f626e6663216c6062">[email protected]</a>',
        age: 35,
    },
    {
        name: 'John',
        email: '<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="2e444146405d41406e434f4742004d4143">[email protected]</a>',
        age: 25,
   }];

My task is to identify duplicate entries within this array by comparing all the fields - name, email, and age.

To address this, I have implemented a function to check for duplicate values, but now I need to incorporate multiple conditions into it. How can I achieve this?

 const unique    = new Set();

 const showError = this.users.some(element => unique.size === unique.add(element.name).size);

Since I have only checked for duplicates based on the name field, I also require validation for email and age. What approach should I take for this multi-condition verification process?

javascript arrays angular typescript duplicates

Answer 1

Answer №1

To determine the status, maintain a counter while comparing objects. Since every object will be equal to itself, check if the counter is greater than 1 to determine the status.

const status = users.some(user => {
  let counter  = 0;
  for (const iterator of users) {
    if (iterator.name === user.name && iterator.email === user.email && iterator.age === user.age) {
      counter += 1;
    }
  }
  return counter > 1;
});

Answer 2

To determine the status, maintain a counter while comparing objects. Since every object will be equal to itself, check if the counter is greater than 1 to determine the status.

const status = users.some(user => {
  let counter  = 0;
  for (const iterator of users) {
    if (iterator.name === user.name && iterator.email === user.email && iterator.age === user.age) {
      counter += 1;
    }
  }
  return counter > 1;
});

Answer 3

Answer №2

var usersData = [
  {
    name: 'Alex',
    email: '<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="b9c2c8c7ccf9c6c8c0c580cdc1c3">[email protected]</a>',
    age: 28,
  },
  {
    name: 'Emma',
    email: '<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="356d60726162637560">[email protected]</a>',
    age: 31,
  },
  {
    name: 'Alice',
    email: '<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="8adbb0aba4a5aab9beb4bccbc6cab8bffaca324f4341">[email protected]</a>',
    age: 34,
  },
  {
    name: 'Alex',
    email: '<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="f59bd19197b69b93939fd3909597">[email protected]</a>',
    age: 28,
  },
  {
    name: 'Claire',
    email: '<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="86efe5eae1c4eb e5ede8aa }," 15) "> [email protected] </A>',
    age: 30,
  },
];

// function complexity is based on the number of user data items
var newData = getUniqueData(usersData, 'email');
console.log(newData)

function getUniqueData(array, keyField) {
  var uniqueItemsArray = [];
  var itemMap = new Map();

  array.forEach((item, index) => {
    if (index === 0) {
      itemMap.set(array[index].email, array[index].email);
      uniqueItemsArray.push(array[index]);
    }
    
    if (!itemMap.get(item[keyField])) {
      itemMap.set(item[keyField], item[keyField]);
      uniqueItemsArray.push(item);
    }
  });
  
  return uniqueItemsArray;
}

Answer 4

var usersData = [
  {
    name: 'Alex',
    email: '<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="b9c2c8c7ccf9c6c8c0c580cdc1c3">[email protected]</a>',
    age: 28,
  },
  {
    name: 'Emma',
    email: '<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="356d60726162637560">[email protected]</a>',
    age: 31,
  },
  {
    name: 'Alice',
    email: '<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="8adbb0aba4a5aab9beb4bccbc6cab8bffaca324f4341">[email protected]</a>',
    age: 34,
  },
  {
    name: 'Alex',
    email: '<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="f59bd19197b69b93939fd3909597">[email protected]</a>',
    age: 28,
  },
  {
    name: 'Claire',
    email: '<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="86efe5eae1c4eb e5ede8aa }," 15) "> [email protected] </A>',
    age: 30,
  },
];

// function complexity is based on the number of user data items
var newData = getUniqueData(usersData, 'email');
console.log(newData)

function getUniqueData(array, keyField) {
  var uniqueItemsArray = [];
  var itemMap = new Map();

  array.forEach((item, index) => {
    if (index === 0) {
      itemMap.set(array[index].email, array[index].email);
      uniqueItemsArray.push(array[index]);
    }
    
    if (!itemMap.get(item[keyField])) {
      itemMap.set(item[keyField], item[keyField]);
      uniqueItemsArray.push(item);
    }
  });
  
  return uniqueItemsArray;
}

Answer 5

Answer №3

To eliminate duplicate entries, utilize the following code snippet:

const removeDuplicates = (array, key) => {
    let lookup = {};
    return array.filter(obj => !lookup[obj[key]] && lookup[obj[key]] = true);
}

Answer 6

To eliminate duplicate entries, utilize the following code snippet:

const removeDuplicates = (array, key) => {
    let lookup = {};
    return array.filter(obj => !lookup[obj[key]] && lookup[obj[key]] = true);
}

Answer 7

Answer №4

Give this a shot:

Let's attempt this solution:
const flagError: boolean = Array.from(new Set(players.map(player => JSON.stringify(player)))).length != players.length;

Answer 8

Give this a shot:

Let's attempt this solution:
const flagError: boolean = Array.from(new Set(players.map(player => JSON.stringify(player)))).length != players.length;

Answer 9

Answer №5

let countOccurrences = users.reduce(function(counts, item) {
    if (item in counts) {
        counts[item] += 1;
    } else {
        counts[item] = 1;
    }
    return counts;
}, {});

let resultList = [];

for (let key in countOccurrences) {
    if (countOccurrences[key] > 1) {
        resultList.push(key.split(",").map(function(item) {
            return parseInt(item);
        }));
    }
}

console.log(resultList);

I trust this solution will be of assistance.

Answer 10

let countOccurrences = users.reduce(function(counts, item) {
    if (item in counts) {
        counts[item] += 1;
    } else {
        counts[item] = 1;
    }
    return counts;
}, {});

let resultList = [];

for (let key in countOccurrences) {
    if (countOccurrences[key] > 1) {
        resultList.push(key.split(",").map(function(item) {
            return parseInt(item);
        }));
    }
}

console.log(resultList);

I trust this solution will be of assistance.

Discovering duplicates in an array list with Angular 6 by using the 'some' method

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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