Question

提前感谢您提供任何帮助我是javascript的新手，所以如果我的某些术语有误，请耐心等待。我有下面的代码和函数，需要将函数run的结果传递给函数AddToCart的arameter。我可以让两个函数独立工作，id =“resultPrintValue”总是返回正确的数字值。基本上我如何将这个值输入AddToCart参数？我已经看到了类似的问题，并尝试了一些建议，例如将函数放入参数但所有返回非数字（NaN） - 我似乎缺少了一些东西。

<!-- select option - calls function run onchange -->

<select name="Print" id="Print"  onchange="run()" > 
<option value="0">select print size </option>        
<option  value="1">Lush Tapestry Print on Paper 50cm x 25cm £125</option> 
<option  value="2">Another print £25</option>
<option  value="3">he original £4000000</option>
<select>

<!-- code below returns the value (0-3) correctly of selected option. Need to pass this result in function AddToCart -->

<p>Your id is: </p><p id="resultPrintValue"> </p>  


<!-- Stuck with code  to put value in parameter of function AddToCart - If I hard code a number 0-3 then AddToCart works fine -->


functions are as below

function run() {
document.getElementById("resultPrintValue").innerHTML = document.getElementById("Print").value;
return (resultPrintValue)
}

function AddToCart(x)
{
var product_index = cart_products.indexOf(x);
if (product_index > -1) 
{
cart_quantities[x]++;
}
else
{
cart_products.push(x);
cart_quantities[x] = 1;
}
ShowPopup("The print was added to your basket!");
UpdateCart();
}

Answer 1

不需要作为参数传入。只需将变量设置为等于run函数的返回值即可。

function AddToCart()
{
var x = this.run()
...
}

Answer 2

        var cart_quantities = [];
        var cart_products = [];
        function run() {
            var value = parseInt(document.getElementById("Print").value, 10);
            document.getElementById("resultPrintValue").innerHTML = value;
            AddToCart(value);
        }
        function AddToCart(x) {
            var product_index = cart_products.indexOf(x);
            if (product_index === -1) {
                cart_products.push(x);
            }

            ShowPopup("The print was added to your basket!");
            UpdateCart();
        }

如何将所选选项值传递给新函数的参数

2 个答案: