CODEWITHSUNDEEP
javascriptarraysnode.js
platinums
platinums

Reputation: 673

Match arrays efficiently, drop found keys in 2nd array

Essentially i have 2 arrays. the resulting unmatched array has duplicates, it should drop item in the array once found, which will lead to the countB variable being smaller once it is finished and no duplicates i the unmatched array

const arr1 = ['Bill', 'Bob', 'John'];
const arr2 = ['Bill', 'Jane', 'John'];
const matched = [];
const unmatched = [];
countA = 0;
countB = 0;
/* Result expected
matched = [Bill, John]
unmatched = [Bob, Jane] */

arr1.forEach((e1) => {
countA++;
  for (const e2 of arr2) {
    countB++;
    if (e1 == e2) {
      matched.push(e1);
      break;
    } else {
      unmatched.push(e2);
     }
  }
});
console.log("unmatched",unmatched);
console.log("matched", matched);
console.log(`Counts  ForEach Loop A:${countA} For In Loop B:${countB}`);

The Result expected are two arrays:

    matched = [Bill, John]

    unmatched = [Bob, Jane]

Upvotes: 1

Views: 54

Answers (2)

Nina Scholz
Nina Scholz

Reputation: 386660

You could take a Set and check if the actual value of the second array is in the set or not. Take the array as required and push the element to it.

const
    array1 = ['Bill', 'Bob', 'John'],
    array2 = ['Bill', 'Jane', 'John'],
    set1 = new Set(array1),
    matched = [],
    unmatched = [];

array2.forEach(v => (set1.delete(v) ? matched : unmatched).push(v));
unmatched.push(...set1);

console.log(matched);
console.log(unmatched);

Upvotes: 1

Kai Lehmann
Kai Lehmann

Reputation: 508

Use the Array.prototype.indexOf() for that

for ( let i = 0; i = arr1.length; i++ ) {
    if ( arr2.indexOf( arr1[i] ) > -1 )
        matched.push( arr1[i] );
    else
        unmatched.push( arr[i] );
}


const arr1 = ['Bill', 'Bob', 'John'];
const arr2 = ['Bill', 'Jane', 'John'];
const matched = [];
const unmatched = [];
countA = 0;
countB = 0;
/* Result expected
matched = [Bill, John]
unmatched = [Jane] */

for (let i = 0; (i < arr1.length); i++) {
    countA++;
  if (arr2.indexOf(arr1[i]) > -1) matched.push(arr1[i] );
  else unmatched.push(arr1[i]); countB++;
}
console.log('unmatched', unmatched);
console.log('matched', matched);
console.log(`Counts  ForEach Loop A:${countA} For In Loop B:${countB}`);

Upvotes: 0

Related Questions