Question

我要求用户输入第一个电话号码。然后，我要求提供比第一个更大的数字。将所有数字从第一个数字乘以第二个，然后输出结果。

我将其作为while循环工作，但需要将其切换为for循环。当我尝试将其切换为for循环时，我不断得到错误的乘法值。不知道需要做什么。

const INITIAL_VALUE = 0;

// declare variables
var number1;
var number2;
var multiply;
var middlePoint;

// initialize sum
multiply = INITIAL_VALUE;

// prompt user to enter two numbers
number1 = prompt("Enter first number: ");
number2 = prompt("Enter a number bigger than first number: ");

// convert user input into numbers
number1 = Number(number1);
number2 = Number(number2);

// assign middlePoint
middlePoint = number1;

// display number1
document.write(number1);

// assign multiply and increment middlePoint
multiply = middlePoint;
middlePoint++;

// while loop to display numbers in between and multiply
//**NEEDS TO BE A FOR LOOP, NOT A WHILE LOOP**
while (middlePoint < number2) {
    document.write(" * " + middlePoint);
    multiply *= middlePoint;
    middlePoint++;
}

// add multiply to number2 for final multiplication total
multiply *= number2;

// display number2 and final multiplication total
document.write(" * " + number2 + " = " + multiply);

Answer 1

欢迎使用StackOverflow！

要切换到for循环，只需确保循环数与while循环相同即可。在这种情况下，要进行的循环数为number2 - number1 - 1或number2和number1之间的数量。因此，您的for循环将是：

for (var i=0; i<number2-number1-1; i++) {
    document.write(" * " + middlePoint);
    multiply *= middlePoint;
    middlePoint++;
}

Answer 2

当前，您的代码编写为经过while循环。在检查布尔条件时，过渡到for循环比使用while循环更麻烦。但是，如果您真的想要for循环，请执行以下操作：

for (;middlePoint < number2;) {
    document.write(" * " + middlePoint);
    multiply *= middlePoint;
    middlePoint++;
}

Answer 3

您可以使用以下代码将所有数字从n1乘以n2：mul将包含乘法结果：

var mul = 1;
    var firstNumber = 0;
    var secondNUmber = 0;
    var firstNumberStr = '';
    var secondNUmberStr = '';

    // prompt user to enter two numbers
    firstNumberStr = prompt("Enter first number: ");

    while(isNaN(firstNumberStr)){
        firstNumberStr = prompt("Enter Correct first number: ");
    }

    secondNUmberStr = prompt("Enter a number bigger than first number: ");

    while(isNaN(secondNUmberStr) || parseInt(firstNumberStr) >= parseInt(secondNUmberStr)){
        secondNUmberStr = prompt("Enter a number bigger than first number: ");
    }

    firstNumber = parseInt(firstNumberStr); 
    secondNUmber = parseInt(secondNUmberStr);
    
    for(;firstNumber <= secondNUmber;){
        mul *= firstNumber;
        firstNumber++   
    } 
    
    alert(mul);

Answer 4

您的代码可以如下修改：

// declare variables
var number1;
var number2;
var multiply;
var middlePoint;
const INITIAL_VALUE = 0;
// initialize sum
multiply = INITIAL_VALUE;

// prompt user to enter two numbers
number1 = prompt("Enter first number: ");
number2 = prompt("Enter a number bigger than first number: ");

// convert user input into numbers
number1 = Number(number1);
number2 = Number(number2);

// assign middlePoint
middlePoint = number1;

// display number1
document.write(number1);

// assign multiply and increment middlePoint
multiply = middlePoint;
middlePoint++;

// while loop to display numbers in between and multiply
for (var i=0;middlePoint < number2; i++) {
    document.write(" * " + middlePoint);
    multiply *= middlePoint;
    middlePoint++;
}

// add multiply to number2 for final multiplication total
multiply *= number2;

// display number2 and final multiplication total
document.write(" * " + number2 + " = " + multiply);

Answer 5

您可以这样做：

let number1, number2, result, resultText;

// prompt user to enter two numbers
number1 = prompt('Enter first number: ');
number2 = prompt('Enter a number bigger than first number: ');

// convert user input into numbers
number1 = Number(number1);
number2 = Number(number2);

// Initialize result and resultText
result = number1;
resultText = '' + number1; 

// for loop to display numbers in between and multiply
for (let i = 1; i <= number2 - number1; i++) {
  const temp = number1 + i;
  result *= temp;
  resultText += ' * ' + temp;
}

// display final multiplication total
resultText += ' = ' + result;
document.write(resultText);

Answer 6

在这里找到for循环中给定两个数字之间所有数字的乘积，简化代码

var num1 = 10;
var num2 = 20;
var product = 1;

document.write(num1);
num1 ++; 

for (;num1 <= num2;) {
    document.write(" * " + num1);
    product *= num1;
    num1++;
}

// display final product
document.write(" = " + product);

将for循环中给定两个数字之间的所有数字相乘

6 个答案: