int totalSum = 0;
int groupSum = 0;
for(int i = 0; i < arr.length; i++) {
for(int j = 0; j< arr[i].length; j++) {
System.out.println(arr[i][j]);
groupSum += arr[i][j];
}
totalSum += groupSum;
groupSum = 0;
}
9.11随机点名器
public class Demo {
public static void main(String[] args) {
String[] students = {"张三","李四","王五"};
Random ran = new Random();
int num = ran.nextInt(students.length);
System.out.println(students[num]);
}
}