class Solution {
    public int removeDuplicates(int[] nums) {        
        ArrayList<Integer> al = new ArrayList<Integer>();
        for(int i=0;i<nums.length;i  ){
            if(!al.contains(i)){
                al.add(i);
            }
        }

        for (int i=0; i<al.size(); i  ) {
            System.out.print(al.get(i));
        }
        Integer[] arr = new Integer[al.size()];
        arr = al.toArray(arr);
        
        return   arr;    
    }
}

I am not understanding where I am going wrong. Below is my error:

Line 16: error: incompatible types: Integer[] cannot be converted to int
    return   arr;

CodePudding user response：

Instead of using Integer[] class using the int[] to create an array and change the code accordingly or else change the return type of function from int[] to Integer[].

Your can change like this,

static int[] your_Func_Name() {
   //Your code
}

Or Else,

ArrayList<Integer> al = new ArrayList<Integer>();
        for(int i=0;i< nums.length;i  ){
            if(!al.contains(i)){
                al.add(i);
            }
        }
        for(int i=0; i<al.size(); i  ){
            System.out.print(al.get(i));
        }

        //Initializing the array using int[] and not Integer[]

        int[] arr = new int[al.size()];

        //ArrayList al elements are manually copied to array

        for (int i = 0; i < arr.length; i  ) {
            arr[i] = al.get(i);
        }

        return arr;

CodePudding user response：

Change the return type of your method from public int removeDuplicates(int[] nums) to public Integer[] removeDuplicates(int[] nums)

The error is due to the return value not matching the return type of the method.