Sep 2, 2015 · If you only need string values in the array, the following will work: function hasDuplicates(array) { var valuesSoFar = Object.create(null); for (var i = 0; i < array.length; …

Jun 9, 2015 · To find all duplicates in a JavaScript array of objects based on a specific property (in this case, "name"), you can use a combination of reduce() and filter() functions.

Oct 14, 2009 · You can check whether any array values are identical using the identity operator (===). Sorting an array of objects to bring duplicates to the start requires knowledge of the …

Apr 7, 2025 · In JavaScript, array methods such as filter () and indexOf () can be used to find duplicates in a concise way. filter () creates a new array containing elements that satisfy a …

Mar 14, 2022 · To find duplicates in an array using JavaScript, combining the filter() and indexOf() methods provides an elegant solution. The filter() method creates a new array with all …

Learn how to find duplicate values in a JavaScript array with this comprehensive guide, including examples and step-by-step instructions.

Feb 27, 2025 · By iterating over the array and keeping track of seen values, we can efficiently identify duplicates. Implementation: const arr = [1, 3, 5, 7, 1, 3]; const findDuplicates = (arr) => …

May 4, 2023 · We’ve looked at various ways on how to find duplicates in an array in JavaScript. We looked at using the ‘filter’ method, ‘set’ objects, simple objects with keys and finally, …

Mar 24, 2020 · Learn 5 different ways to check if an array contains duplicate elements with example and explanation.

Aug 10, 2020 · There are a couple of ways to count duplicate elements in a javascript array. by using the forEach or for loop. Iterate over the array using a for loop.