20250426

	// char to int
    char ch = '0';
    int chatToInt = Character.getNumericValue(ch);
    
    // ArrayList<Integer> to Integer[]
    List list = new ArrayList<Integer>();
    Integer[] arrInteger = list.toArray(Integer[]::new);
    
	// ArrayList<Integer> sort + ArrayList<Integer> to int[]
    int[] arrInt = list.stream().sorted().mapToInt(Integer::intValue).toArray();