使用条件语句循环

Question

您好，我想学习如何进行 java 循环，该循环将确定数字是奇数还是偶数

   1st value: 8
   2nd value: 15

output:
    8 is even
    9 is odd
    10 is even
    11 is odd
    12 is even
    13 is odd
    14 is even
    15 is odd

Answer 1

你可以这样做：

Scanner input = new Scanner(System.in);

System.out.print("First value: ");

int start = Integer.parseInt(input.nextLine());//Gets the first number

System.out.print("Second value: ");

int end = Integer.parseInt(input.nextLine());//Gets the second number

for(int i = start; i <= end; i++){
    if(i%2==0){//When the number is divided by 2, it gives a remainder of 0. Modulus helps us get the remainder.
        System.out.println(i+" is even");
    }else{//Doesn't satisfy the first condition. It must be odd.
        System.out.println(i+" is odd");
    }
}

我们使用 Scanner 读取用户输入，然后使用 for 循环并利用模数 (%)。模数计算一个数字除以某个数字后的余数。如果一个数除以 2 的余数为 0，这意味着它可以被 2 整除。我们可以构造一个 if 语句来检查它是否可以整除。

测试运行

First value: 1
Second value: 10
1 is odd
2 is even
3 is odd
4 is even
5 is odd
6 is even
7 is odd
8 is even
9 is odd
10 is even

Answer 2

你可以使用 for 循环，这很简单。

for(int i=8;i<=15;i++){
if(i%2==0){
System.out.println(i+"is even");
}else{


System.out.println(i+"is odd");
}
}

我希望你知道如何询问输入，所以只需将其传递到 8 和 15 的位置

Answer 3

短版：

https://www.youtube.com/watch?v=cakN0XC6CcQ

使用 number % 2 == 0 表示偶数。

长版：

// Create a new Scanner() to scan System.in
Scanner scanner = new Scanner(System.in);

// Get the two inputs
int first = scanner.nextInt();
int second = scanner.nextInt();

// Start i as the first number
// While it is less than or equal to the second
// Add one each time
for(int i = first; i <= second; i++) {

    // Is there a remainder from dividing i by 2?
    // If no, it's even
    boolean even = i % 2 == 0;

    // Print it
    System.out.println(i + " is even: " + even);
}

    scanner.close();