hashmap correction at line 17

Firstly, Line 17 in your addCatsToMap function is wrong. You have to put Cats object with key as their name inside hashmap. new HashMap<>() is used only for declaration and not adding elements. use map.put(). whatever you put inside <> is only type identifier which identifies which type is going to be stored in hashmap or any other collection but doesn't actually store the value. To store, use put() function. Secondly, in your above base logic code, you made same mistake inside for loop. You to add in one hashmap and not create a new hashmap for every object. Also, you cannot use return like that inside a loop. You have to understand what exactly return keyword does - it breaks out of the function and returns value, your loop will stop then and there as return is called. Store the value in Hashmap using put and then return the complete hashmap. refer to below links for return keyword - https://stackoverflow.com/questions/10661081/java-does-returning-a-value-break-a-loop https://www.geeksforgeeks.org/return-keyword-java/

whats wrong with hashmap variable "map" at line 16; error on: line 16 & 19 line 4: has hashmap "map" variable.

public static void main(String[] args) throws Exception {
       String[] cats = new String[]{"Tiger", "Missy", "Smokey", "Marmalade", "Oscar", "Snowball", "Boss", "Smudge", "Max", "Simba"};

       HashMap<String, Cat> map = addCatsToMap(cats);

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


   public static HashMap<String, Cat> addCatsToMap(String[] cats) {
       //write your code here
       for(String x: cats)
       {
           map.put(x, new Cat(x));//
           //new HashMap<x, Cat()>(); //
       }
      return map;
   }


   public static class Cat {
       String name;

       public Cat(String name) {
           this.name = name;
       }

       @Override
       public String toString() {
           return name != null ? name.toUpperCase() : null;
       }
   }

Recall the concept about scope of variables. If not familiar, you can refer to below links or search google - https://www.geeksforgeeks.org/variable-scope-in-java/ http://www.javawithus.com/tutorial/scope-and-lifetime-of-variables You've declared map inside main function and trying to access it inside addCatsToMap function. Create a new HashMap inside addCatsToMap function, put values in it and then return the new map. addCatsToMap function will return the value of new map and store in map declared in main function.

google keywords attempeted(not each word is perfectly correct): https://www.google.com.pk/search?ei=fJyuW7KXDs2g5wKuvqZQ&q=hashmap+decalare+and+assign+values+in-directly+functions&oq=hashmap+decalare+and+assign+values+in-directly+functions&gs_l=psy-ab.3...27471.40424.0.40735.29.25.0.0.0.0.615.3877.3-4j4j1.9.0....0...1.1.64.psy-ab..24.2.742...33i10k1.0.zRcdom-aJX8 refrence: https://stackoverflow.com/questions/6802483/how-to-directly-initialize-a-hashmap-in-a-literal-way

public static HashMap<String, Cat> addCatsToMap(String[] cats) {
        //write your code here

      HashMap<String, Cat> myMap = new HashMap<String,Cat>();
        for(String x: cats)
        {
            myMap.put(x, new Cat(x));//
            //new HashMap<x, Cat()>(); //
        }
       return myMap;
    }

public static HashMap<String, Cat> addCatsToMap(String[] cats) { //write your code here HashMap<String, Cat> map = new HashMap<>(); for (int i = 0; i < cats.length; i++){ map.put(cats[i], new Cat(cats[i])); } return map; }