Map HashMap Scanner

Question

This is what the output should be:: This is my code: first problem is that i cant combine string and integer(ex. 555-999 ) second problem is the output two name is showing (ex. name: name:) what is the right code for it.. thank you for the answer

Aman Gupta · Answer

Hi Justine here is the solution to your problem or a file is attached for your reference. import java.util.HashMap; import java.util.Map; import java.util.Scanner; import java.util.Set; public class Test { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(System.in); //for input from user Map hm = new HashMap (); //loop to enter the desired values for ( int i=0; i { System.out.print((i+1)+ . +  student number:  ); int num = sc.nextInt(); //int value sc.nextLine(); // to eliminate any cohesion System.out.print( name:  ); String name = sc.nextLine(); // string value hm.put(num name); //add value to hashmap } //Fetch values in an ordered manner Set id = hm.keySet(); for (Integer i : id) { System.out.println(i + 	 + hm.get(i)); //each pair in new line } System.out.println(); } }

Aman Gupta · Answer

Yes for that take user input in other variable (say id) and pass that like this hm.remove(id). Remember id as integer variable.

Aman Gupta · Answer

hm.remove(Object key) will work only if you pass Key as paraneter. Here pass hm.remove(5252) and your data with value Mario will be removed.

Guest User · Answer

hey Aman sorry for the trouble.. what you mean is i should type hm.remove(5252) and hm.remove(dfd).?

Aman Gupta · Answer

Hi Justin Always remember you can only remove the object from hashmap entry through hashmap.remove(Object key) If key is valid then your data will be removed from map else it will return Null.So in this case you should use hm.remove(2018-0134) this will work as well as for confirmation print the new map again.

Guest User · Answer

I'm trying to remove the third output of keys and value using the hm.remove(3); but it wont work please help.. i badly really want to know..

Map, HashMap, Scanner