package lesson_3;

public class Frame_15 {

	public static void main(String[] args) {
		// 
		
		int[] data_1= new int[] {3,5,-6,5,12,500};
		int[] data_2= new int[] {0};
		int[] data_3= new int[] {};
		int[] data_4= new int[] {-3};
		int[] data_5= new int[5];
		int[] data_6= null;
		
		
		System.out.println(avarage(data_1));
		System.out.println(avarage(data_2));
		System.out.println(avarage(data_3));
		System.out.println(avarage(data_4));
		System.out.println(avarage(data_5));
		System.out.println(avarage(data_6));
		
		
	}
	static double avarage(int[] data){
		double aver=-1;
		double sum = 0.0;
		if (data == null||data.length<=0){return aver;}
		for (int d:data){
			sum+=d;
			}
		aver = sum/data.length;
		return aver;
	}

}