Check for duplicates within 2 arrays by implementing a filtering process

Question

Check for duplicates within 2 arrays by implementing a filtering process

I am trying to figure out how to compare two arrays to determine if there are any duplicates within them.

 const result = this.specialRange.filter(d => !dayMonth.includes(d));

What I have attempted so far just returns the entire array back to me, but I only want to know if there is a duplicate: yes -> do something, no -> don't do anything.

   var dayMonth: any[] = ["1201","1202","1203","1204","1205"];
   specialRange: any[] = ["1201","1202","1203","1204"];

Depending on the leading argument, it either returns the entire special range or dayMonth, but I simply want a true/false result if there is a duplicate.

Both arrays have similar values, even though they are of type Any. This is just for practical learning purposes at the moment.

The values always follow a format like "1201,1202,1203,1204" representing MM/DD.

Update for Pyth:

When testing:

dayMonth = 1215,1216

specialRange =

1215,1216,1217,1218,1219,1220,1221,1222,1223,1224,1225,1226,1227,1228,1229

Modified method:

for(let v of dayMonth){
      if(this.specialRange.includes(v)){
        alert('true');
      }
      else{
        alert('false')
      }

    }

Result => False/False

For some reason, my console does not log anything when I use console.log.

javascript typescript

Answer 1

Answer №1

Although there may be more efficient methods, here's a simple way to tackle this problem:

const a1 = [1200, 1201, 1202, 1203];
const a2 = [1202, 1203, 1204];
// Expected Duplicates: [1202, 1203]
// Expected Unique: [1200, 1201, 1204]


function filter_duplicates(arr1, arr2) {
  let duplicates = [];
  let unique = [];
  for (let v of arr1) {
    // Check if value in arr2, classify as duplicate or unique
    if (arr2.includes(v)) {
        duplicates.push(v);
    } else {
        unique.push(v);
    }
  }
  for (let v of arr2) {
    // Add unique values from arr2
    if (!duplicates.includes(v)) {
      unique.push(v);
    }
  }
  console.log("Duplicates: ", duplicates);
  console.log("Unique: ", unique);
  return {duplicates: duplicates, unique: unique}
}
filter_duplicates(a1, a2);

Answer 2

Although there may be more efficient methods, here's a simple way to tackle this problem:

const a1 = [1200, 1201, 1202, 1203];
const a2 = [1202, 1203, 1204];
// Expected Duplicates: [1202, 1203]
// Expected Unique: [1200, 1201, 1204]


function filter_duplicates(arr1, arr2) {
  let duplicates = [];
  let unique = [];
  for (let v of arr1) {
    // Check if value in arr2, classify as duplicate or unique
    if (arr2.includes(v)) {
        duplicates.push(v);
    } else {
        unique.push(v);
    }
  }
  for (let v of arr2) {
    // Add unique values from arr2
    if (!duplicates.includes(v)) {
      unique.push(v);
    }
  }
  console.log("Duplicates: ", duplicates);
  console.log("Unique: ", unique);
  return {duplicates: duplicates, unique: unique}
}
filter_duplicates(a1, a2);

Answer 3

Answer №2

const filteredResult = this.specialRange.filter(item1 => dayMonth.includes(item1));

After filtering, there may be duplicate items. To check for duplicates, simply compare the length of the filtered result array. If the length is greater than 0, return true, otherwise return false.

Answer 4

const filteredResult = this.specialRange.filter(item1 => dayMonth.includes(item1));

After filtering, there may be duplicate items. To check for duplicates, simply compare the length of the filtered result array. If the length is greater than 0, return true, otherwise return false.

Check for duplicates within 2 arrays by implementing a filtering process

Answer №1

Answer №2

Similar questions

Effective approach to exchange information among controllers in AngularJS

Exploring the limitations of middlewares in supporting independent routers

Is it possible to run two commands in npm scripts when the first command initiates a server?

Error encountered: Circular reference issue was encountered when attempting to retrieve navigator.plugins with the use of Selenium and Python

Using JavaScript to toggle the visibility of grids depending on the radio button choice and then triggering this action by clicking on the search button

How to pass data/props to a dynamic page in NextJS?

Removing an element with a specific class that was created with Javascript can be done by clicking outside the box

What are the steps to successfully launch a Node.js / Express application with typescript on heroku?

The Angular 2 service is not transmitting the POST data in the correct format, although it functions properly when transmitted through PostMan

The jQuery validation feature is failing to function properly within a bootstrap modal

Dealing with Unexpected Timeout Errors and Memory Leaks in Express/Typescript Using Jest, Supertest, and TypeORM

Are there differences in alignment?

Using AngularJS to inject a variable into the standard filter

Wrap the words around to fit a rectangle with a specific ratio, rather than a specific size

Tips for modifying the type definition of a third-party library in a Vue project built with Create-Vue

The mouse event listener fails to function in plain JavaScript

The boolean type in TypeScript is throwing an error because it does not have any call

Utilizing a custom filter for object manipulation within Vuetify's v-autocomplete

Having trouble establishing a connection with the SignalR client using an npm package

What is the best way to generate a one-level breadcrumb using Jquery?