I need to count the no of duplicates in an multidimensional array and give alert if duplicates found.
Arr =[[2,"sk"],[3,"df"],[7,"uz"],[3,"df"],[7,"gh"]]
Only exact count require like [3,"df"] at 2 nd position equals [3,"df"], at 4 th position Expected Output Count :1 Alert duplicate data found
You could map to a stringified version of the inner arrays and then create a Set of these and then calculate the difference in length of the items in the set and the original array:
const input = [
[2, "sk"], [3, "df"], [7, "uz"], [3, "df"], [7, "gh"],
[5, "df"], [21, "sk"], [2, "1sk"]
];
const duplicate_count = input.length - new Set( input.map(JSON.stringify) ).size;
console.log(duplicate_count);
You could map to get only the values, then sort, then count duplicates with reduce like this:
const input = [
[2, "sk"],
[3, "df"],
[7, "uz"],
[3, "df"],
[7, "gh"],
];
const result = input
.map(([, value]) => value)
.sort()
.reduce(
(acc, cur, i, { [i - 1]: last }) => (cur === last ? acc + 1 : acc),
0
);
console.log(`Count: ${result}${result && ' Alert duplicate data found'}`);Here's a simple little function to return the number of dupes found
let arr =[[2,"sk"],[3,"df"],[7,"uz"],[3,"df"],[7,"gh"],[2,"sk"],[7,"uz"]]
function getNumDupes(a) {
return a.length-
arr.reduce((b,a)=>{if (!b.includes(a.join(""))) b.push(a.join("")); return b;},[]).length
}
console.log(getNumDupes(arr) + ' duplicates found');
[[2,"sk"],[5,"df"],[7,"uz"],[3,"df"],[7,"gh"]]would this have one duplicate or no duplicates? ([5,"df"]vs[3,"df"])[2,"sk"]and["sk",2]?[21, "sk"]and a[2, "1sk"]?