简答题 针对以下代码,请分析代码中存在的问题和缺陷.public class getScoreAverage{ public float getAverage( int [] scores ){ if (scores==null || scores.length==0){ throw new NullPointerException____;}float sum = 0.0F;int j=scores.length;for (int i=1; i<j; i++){ sum += scores[i];}return sum/j;}}