You have used incorrect symbol in your code like < >. The for is improper and not completed. Moreover, you have open and close braces properly. Anyways, we have modified your code. Here it is:

class DemoArray {
    public static void main(String args[]) {
        int arr[]={12,13,14,15}; 
        int n=arr.length; 
        System.out.println("length of array:"+n);
        for(int i=0;i<n;i++){ 
          System.out.println(arr[i]);
        }
    }
}