How Can I Efficiently Count the Frequency of Array Elements in JavaScript?

Counting the Frequency of Array Elements

In JavaScript, counting the occurrence of elements within an array can be achieved with the help of objects. By leveraging the key-value pair structure of objects, we can create a dynamic data structure that maps elements to their respective frequencies.

To illustrate this solution, consider the provided example array: [5, 5, 5, 2, 2, 2, 2, 2, 9, 4]. We create an empty object called 'counts' to store the element frequencies.

We then iterate through each element in the array using a for-of loop. For each element 'num', we check if it already exists as a key in the 'counts' object. If it does, we increment its value by 1; otherwise, we initialize it to 1.

After processing all elements, the 'counts' object contains the unique elements as keys and their corresponding frequencies as values. We can then log the object to the console to see the count for each element.

By using this approach, we can efficiently determine the frequency of elements in an array and store the results in a structured manner, providing a concise and interpretable representation of the element distribution.

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