Advanced Java Arrays Excercise

public static void main(String[] args) {
        
  Scanner scanner = new Scanner(System.in);
  int[] ar = new int[0];
  
  Outer : while (true){
    System.out.print("Enter Number : ");
    int x = scanner.nextInt();	
    
    
    // program exits if user enters '-1'
    if(x == -1){
    break;
    }
  
    // checking the duplicates.
    Inner : for (int j = 0; j < ar.length; j++){
    
    if(ar[j] == x){
      System.out.println("Duplicate Number");
      continue Outer;
    }
    }
    
    // Extending the array by creating new array.
    int[] cr = new int[ar.length + 1];
    
    // Copying values from old array to new array.
    for (int k = 0; k < ar.length; k++){
    cr[k] = ar[k];
    }
    
    // Assigning user entred value to the last index.
    cr[cr.length - 1] = x;
    
    // Changing reference of the new array to old array's reference.
    ar = cr;
    
  }
  
  System.out.println(Arrays.toString(ar));
  System.out.println("Array Length : "+ar.length);
  
  }