Question

我正在尝试加载一个提示，询问用户想要输入多少个数字，然后会弹出提示输入的次数，并且每次进入数组时都能输入一个数字然后是最后一个显示总和的警示框。

如何构建此数组然后获得总和？

要获得我使用的第一个numberOfNumbers：

function hello()
{
var numberOfNumbers=prompt("How many numbers would you like to add?")
alert(y)
}

var sum = [];
for (var i = 1; i <= numberOfNumbers; i++) {
   sum.push(i);
}

Answer 1

为什么要构建数组？

var numberOfNumbers = parseInt(prompt("How many numbers would you like to add?"));

if(isNaN(numberOfNumbers) || numberOfNumbers <= 0) {
  alert("Invalid number!");
}
else {
  var sum = 0, i;
  for (i = 1; i <= numberOfNumbers; i++) {
     sum += i;
  }
  alert(sum);
}

另外，正如@JohnRummuel所指出的那样，在你的代码中numberOfNumbers不存在于功能块的范围之外，因此for循环不会“看到”它。

Answer 2

var numberOfNumbers = parseInt(prompt("How many numbers would you like to add?"));
alert(numberOfNumbers);

var sum = 0;
for (var i = 1; i <= numberOfNumbers; i++) {
   sum += parseInt(prompt("Enter a number"));
}
alert("The sum of numbers you entered is " + sum);

Answer 3

这是你想要做的吗？

function hello() { 
    var numberOfNumbers = prompt("How many numbers would you like to add?"); 
    return parseint(numberOfNumbers, 10);
}

function sumNumbers() {
    var numbers = []; 
    var number = 0; 
    var numberOfNumbers = hello(); 
    for (var i = 1; i <= numberOfNumbers; i++) { 
        number = parseInt(prompt("Enter a number to add"), 10); 
        numbers.push(number); 
    } 
    alert(numbers.reduce(function(a, b) { return a + b; })) ; 
}

使用提示，选择数字，将数字添加到数组，然后显示总数

3 个答案: