Frequency of Numbers in a 1D Array

Question

its been 6 hours since I have been writing the code but to no avail, I don\'t no where I am making the mistake but I am making some. Its a frequency output program and output sh

Answer 1

/**
 * The methods counts the frequency of each element in an array.
 * 
 * Approach: The method checks if the element is already present in the Map of frequency.
 * If it is not present, add it to the map with the frequency 1 else put it in the map with 
 * an increment by one of it's existing frequency.
 * 
 * @param arr list of elements
 * @return frequency of each elements
 */
public static Map countFrequency(int[] arr) {
    Map frequency= new HashMap();
    for(int i = 0; i < arr.length; i++) {
        if(frequency.get(arr[i])==null) {
            frequency.put(arr[i], 1);
        }
        else {
            frequency.put(arr[i],frequency.get(arr[i])+1);
        }
    }
    System.out.println("\nMap: "+frequency);
    return frequency;
}