What performance optimization does the following code implement?
function processValues(values) {
// Convert array to Set for faster lookups
const valueSet = new Set(values);
return function isValueIncluded(value) {
return valueSet.has(value);
};
}
This code implements algorithmic complexity reduction by converting an array to a Set for O(1) constant-time lookups instead of O(n) linear-time array searches. When you need to repeatedly check if a value exists in a collection, using array methods like includes() or indexOf() is inefficient as they must scan through the entire array each time, resulting in O(n) time complexity. By converting the array to a Set once and then using the has() method for subsequent lookups, the time complexity is reduced to O(1), providing significantly better performance, especially for large datasets. This technique is a classic example of trading a one-time conversion cost for much faster subsequent operations.