我在编写阶乘程序时遇到困难

Question

程序应该要求用户输入一个正整数并打印一个阶乘表。如果输入小于 0，输出或程序应该停止。给我一个正整数：5输出：5！= 5 x 4 x 3 x 2 x 15 的阶乘是 120给我一个正整数：-5输出：无效输入！程序停止ps：我是初学者。我正在使用 Netbean IDE

Answer 1

这应该有效。只需循环数字。

var input = prompt("What number would you like me to give you the factorial of?");

if (input > 0) {

  var answer = 1;

  var string = input + " =";

  for (var i = input; i >= 1; i--) {

    answer *= i;

    string += " " + i

    if (i != 1) {

      string += " x"

    }

  }

  console.log(string)

  console.log("The factorial of " + input + " is " + answer)

} else {console.log("Invalid input! Program stopped.")}

Java（假设输入在变量中input）：

if (input > 0) {

  int answer = 1;

  String stringAnswer = input + " =";

  for (int i = input; i >= 1; i--) {

    answer *= i;

    stringAnswer += " " + i

    if (i != 1) {

      stringAnswer += " x"

    }

  }

  System.out.println(stringAnswer)

  System.out.println("The factorial of " + input + " is " + answer)

} else {System.out.println("Invalid input! Program stopped.")}

Answer 2

您可以检查数字是否小于 0 否则计算阶乘

let x = prompt('Please enter a positive integer');

if (x < 0) {

  console.log('invalid Input! Programmed Stop')

} else {

  let val = 1;

  for (let k = 1; k <= x; k++) {

    val *= k

  }

  console.log(val)

}