Write a method that groups strings by their length. The method should return a map where keys are string lengths (Integer) and values are lists of strings with that length.
Method Signature
public static Map<Integer, List<String>> groupByLength(List<String> strings)
Examples
Example 1:
Input: ["cat", "dog", "apple", "bat"]
Output: {3: ["cat", "dog", "bat"], 5: ["apple"]}
Explanation: Strings are grouped by their length. Three strings have length 3, and one has length 5.
Example 2:
Input: ["a", "bb", "ccc"]
Output: {1: ["a"], 2: ["bb"], 3: ["ccc"]}
Explanation: Each string has a different length, so each gets its own group.
Example 3:
Input: []
Output: {}
Explanation: Empty input returns an empty map.
Example 4:
Input: null
Output: {}
Explanation: Null input returns an empty map.
Example 5:
Input: ["", "a", ""]
Output: {0: ["", ""], 1: ["a"]}
Explanation: Empty strings have length 0 and are grouped together.
Welcome to Lightning Challenge!
Create an Account
Sign up to track your progress, earn points, and compete with others. Your solutions will be saved automatically.
Create accountHow It Works
- • Write your solution in the code editor
- • Connect your Salesforce org to test
- • Submit to check if your solution passes
- • Use hints if you get stuck
Contest Alert
Contest runs May 1 - 31. Complete challenges to climb the leaderboard!
Only the 31 daily challenges shown during this contest count toward points. Earlier dailies don't carry over.