NOTES

Vectors

Vector is synchronized

String: equalsIgnoreCase

Comparable & comparator

💡 Differences

• Comparator implemented in different class
• Values always stored in collections.(with Strings!)
• comparable implemented in same class.

HashMapClass…

• Unordered
• unsorted
• Allows one null key and multiple null values

public class MapDemo {
								
									public static void main(String[] args) {
										 // Should use put keyword in map
										
										Map<String, String> m = new HashMap<String, String>();
										m.put("Sai", "asdfg");
										m.put("krish", "zxcvb");
										m.put("qwerty", "lkjh");
										m.put("qwerty", "lkj");
										
										System.out.println(m);
									}
								
								}
								
								

Duplicate key, overides the existing

• “qwerty”, “lkjh” overidden to “qwerty”, “lkj”

Here:

Key	Value
qwerty	lkj

Tree Map class

• Sorted

Generics