find_the_difference_between_two_arrays.md

Find the Difference Between Two Arrays

Find the Difference Between Two Arrays

To find the difference between two arrays, use a set to track elements that are in one array but not the other.

Algorithm:

1. Convert one array into a set for efficient lookup.
2. Iterate through the second array and add elements that are not in the set to the result array.
3. Return the resulting array of differences.

Example:

function arrayDifference(arr1, arr2) {
    const set = new Set(arr1);
    return arr2.filter(item => !set.has(item));
}

// Example usage
console.log(arrayDifference([1, 2, 3], [3, 4, 5])); // Output: [4, 5]
console.log(arrayDifference([1, 2, 3, 4], [3, 4, 5])); // Output: [5]

This method has a time complexity of O(n + m), where n and m are the lengths of the two arrays.

Tags: basic, JavaScript, Arrays, Algorithm