Remove Covered Intervals

Problem statement

Given an array intervals where intervals[i] = [li, ri] represent the interval [li, ri), remove all intervals that are covered by another interval in the list.

The interval [a, b) is covered by the interval [c, d) if and only if c <= a and b <= d.

Return the number of remaining intervals.

Example 1:

Input: intervals = [[1,4],[3,6],[2,8]]Output: 2Explanation: Interval [3,6] is covered by [2,8], therefore it is removed.

Example 2:

Input: intervals = [[1,4],[2,3]]Output: 1

Constraints:

• 1 <= intervals.length <= 1000
• intervals[i].length == 2
• 0 <= li <= ri <= 105
• All the given intervals are unique.

My solution

/**
 * @param {number[][]} intervals
 * @return {number}
 */
var removeCoveredIntervals = function(intervals) {
    intervals.sort((a, b) => a[0] - b[0] || b[1] - a[1])
    
    let prevEnd = 0;
    let count = 0;
    
    for (let i of intervals) {
        end = i[1];
        
        if (end > prevEnd) {
            count++;
            prevEnd = end;
        }
    }
    
    return count;
};