Java regular final exam questions type

Java regular exam type

Each title can have a variety of ways, here only gives a method, the code is not optimal, but given ideas

It is calculated from the base 1 to 100 and even and

 public static void main(String[] args) {
  int sum1 = 0;
  int sum2 = 0;
  for (int i = 1; i <= 100; i++) {
   if (i % 2 == 0) {
    sum1 += i;
   }else {
    sum2 += i;
   }
  }
  System.out.println(sum1);
  System.out.println(sum2);
 }

Computing a digital input from the keyboard and calculating elapsed time factorial!

 public static void main(String[] args) {
  long time = System.currentTimeMillis();
  Scanner scanner = new Scanner(System.in);
  System.out.println("请输入要计算的阶乘数：");
  int number = scanner.nextInt();
  long a = sum(number);
  System.out.printf("%d的阶乘的结果是：%s%n",number,a);
  long time1 = System.currentTimeMillis();
  System.out.println("消耗时间" + (time1 - time));
 }
 static long sum(int i){
  if(i == 1){//递归头
   return 1;
  }else {
   return i*sum(i - 1);//递归体
  }
 }

Output prime number within 1-100

public static void main(String[] args) {
  prime:for (int i = 1; i < 100; i++) {
   for (int j = 2; j < i; j++) {
    if(i % j == 0){
     continue prime;  //这里的prime就是的标签       如果被整除就跳出内循环，进入外循环
    }
   }
   System.out.println(i);
  }
 }

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