Exercise 15: Check if Array is Sorted
Problem Statement
Create a function `isSorted(arr, order="asc")` that checks if array is sorted.
Example:
- isSorted([1, 2, 3]) → true
- isSorted([3, 2, 1], "desc") → true
Sample Output:
isSorted([1, 2, 3]) => true isSorted([3, 2, 1], "desc") => true isSorted([1, 3, 2]) => false
Solution
const isSorted = (arr, order = "asc") => {
if (!Array.isArray(arr) || arr.length <= 1) return true;
for (let i = 1; i < arr.length; i++) {
if (order === "asc" && arr[i] < arr[i - 1]) return false;
if (order === "desc" && arr[i] > arr[i - 1]) return false;
}
return true;
};Explanation
Overall Goal:
- Array sorted hai ya nahi check karna (ascending/descending).
Line 1: Function header
const isSorted = (arr, order = "asc") => {
Line 2: Edge cases
if (!Array.isArray(arr) || arr.length <= 1) return true;
Line 3: Iterate
for (let i = 1; i < arr.length; i++)
Line 4-5: Check order
- Ascending/descending check.
Real world:
- Data validation: sorted data checks.
- Algorithms: pre-sorted checks.