Maps & Frequency Counting
Map basics (put/get/remove), entry iteration, word-frequency counter, and TreeMap for sorted view.
What is a Map?
A Map stores key→value pairs. Good choices:
- HashMap: fast, no order.
- TreeMap: keys sorted.
- LinkedHashMap: remembers insertion order.
Common operations
Main operations:
- put(k,v), get(k), containsKey(k), remove(k)
- Size: size()
- Loop: entrySet() for key and value.
All lessons in this course
- Maps & Frequency Counting
- Comparable vs Comparator
- Sorting/Searching with Collections