Summary of its ranges

Given a sorted integer array without duplicates, return the summary of its ranges.

Example
const summaryRanges = nums => {

};

console.log(summaryRanges([0,2,3,4,6,8,9])) 
// ["0","2->4","6","8->9"]

Solution

function summaryRanges(arr) {
  let i = 0;
  const result = [];
  while (i < arr.length) {
    let j = i + 1;
    while (j < arr.length && arr[j] === arr[j - 1] + 1) j++;
    const val = arr[j - 1];
    result.push(i === j-1 ? val.toString() : `${arr[i]}->${val}`);
    i = j;
  }
  return result;
}

Explanation

The summaryRanges function iterates through an array using a while loop. It uses a nested while loop to identify contiguous ranges of numbers. For each range, it constructs a string representing that range and pushes it to a result array. After fully iterating the array, it returns the result array containing the summarized ranges.