TreeMap method in Java

* create
```
import java.util.*;  

class Main{  
    public static void main(String args[]){  
        TreeMap<Integer,String> map=new TreeMap<>();    
        map.put(100,"A");    
        System.out.println(map);    
    }  
}  
```
* iterator
```
import java.util.*;  

class Main{  
    public static void main(String args[]){  
        TreeMap<Integer,String> map = new TreeMap<>();    
        map.put(100,"A");    
        map.put(200,"B");

        Iterator<Map.Entry<Integer, String> > iterator = map.entrySet().iterator();
        while (iterator.hasNext()) {
            Map.Entry<Integer, String> entry = iterator.next();
            System.out.println(entry.getKey() + "->" + entry.getValue());
        }

        for (Map.Entry<Integer, String> entry : map.entrySet()) {
            System.out.println(entry.getKey() + "->" + entry.getValue());
        }

        map.entrySet().forEach(entry -> {
            System.out.println(entry.getKey() + "->" + entry.getValue());
        });
    }  
} 
```
* add
```
import java.util.*;  

class Main{  
    public static void main(String args[]){  
        TreeMap<Integer,String> map = new TreeMap<>();    
        map.put(100,"A");    
        map.put(200,"B");
        
        Set<Map.Entry<Integer, String> > entries = map.entrySet();
        entries.forEach(entry -> {
            System.out.println(entry.getKey() + "->" + entry.getValue());
        });
    }  
}  
```
* change
```
import java.util.*;  

class Main{  
    public static void main(String args[]){  
        TreeMap<Integer,String> map = new TreeMap<>();    
        map.put(100,"A");    

        // put() replace the value if the key is present;
        // but if the key is not present it creates a new record.
        // If an existing key is passed then the previous value gets returned. 
        // If a new pair is passed, then NULL is returned.
        map.put(100,"AA");    
        map.put(200,"B");
        
        // replace() replaces the value of the given key 
        // but if the key is not present it does not create a new record
        // It returns the previous value associated with the key. 
        // If there is no such key mapped, then it returns null.
        map.replace(200, "BB");
        map.replace(300, "C");
        
        // computeIfPresent() changes value if key is present 
        map.computeIfPresent(200,(k,v)->"BBB");
        map.computeIfPresent(300,(k,v)->"CC");
        
        Set<Map.Entry<Integer, String> > entries = map.entrySet();
        entries.forEach(entry -> {
            System.out.println(entry.getKey() + "->" + entry.getValue());
        });
    }  
}  
```
* query
```
import java.util.*;  

class Main{  
    public static void main(String args[]){  
        TreeMap<Integer,String> map = new TreeMap<>();    
        map.put(100,"A");    
        map.put(200,"B");

        System.out.println(map.containsValue("A"));
        System.out.println(map.containsKey(200));
        System.out.println(map.isEmpty());
        System.out.println(map.size());
    }  
}
```
* delete
```
import java.util.*;  

class Main{  
    public static void main(String args[]){  
        TreeMap<Integer,String> map = new TreeMap<>();    
        map.put(100,"A");    
        map.put(200,"B");

        map.remove(200);
        map.clear();
        System.out.println(map);
    }  
}
```