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Question

我遇到以下代码问题。当它运行时，它记录我的三个订单，但我得到一个小数为0.它应该将orderCount 3乘以7.5，因为我调用了函数takeOrder三次。我错过了什么吗？

var orderCount = 0;

function takeOrder(topping, crustType){
    orderCount + 1;
    console.log("Order: " + crustType + " pizza topped with " + topping + ".");
}

function getSubTotal(itemCount) {
    return itemCount * 7.5;
}

takeOrder("mushroom", "stuff crust");

takeOrder("pepperoni", "thin crust");

takeOrder("sausage", "sicilian crust");

console.log(getSubTotal(orderCount));

Answer 1

您需要增加orderCount

orderCount += 1;

Answer 2

orderCount + 1;

不会增加orderCount的值。

使用

orderCount++;

相反，这是

的缩写

orderCount += 1;

是

的缩写

orderCount = orderCount + 1;

Answer 3

var orderCount = 0;

function takeOrder(topping, crustType){
    orderCount ++;
    console.log("Order: " + crustType + " pizza topped with " + topping + ".");
}

function getSubTotal(itemCount) {
    return itemCount * 7.5;
}

takeOrder("mushroom", "stuff crust");

takeOrder("pepperoni", "thin crust");

takeOrder("sausage", "sicilian crust");

console.log(getSubTotal(orderCount));

  

更改orderCount + 1; to orderCount ++;