Question

问题是重复的，对不起。

Answer 1

您的嵌套if永远不会被执行，index不能同时为1和3。我建议您改用switch，它基本上就是您要做的事情：

var productPurchase = readlineSync.question('Would you like to purchase a   product? ');
if (productPurchase == "yes") {
    index = readlineSync.keyInSelect(products, 'What product would you like?');
    switch (index) {
      case 1 : 
        console.log('Thank you, your Drink' + ' has now been dispensed.');
        break;
      case 2 :  
        console.log('Thank you, your Crisps' + ' has now been dispensed.');
        break;
      case 3 :
        console.log('Thank you, your Chocolate' + ' has now been dispensed.');
        break;
      case 4 :   
        console.log('Thank you, your Candy' + ' has now been dispensed.');
        break;
      default :
        console.log('something went wrong'); 
        break;
    }
}

注意：纠正了index的错误用法。 keyInSelect()将索引作为数字返回，而不是数组。

Answer 2

试试这个：

var readlineSync = require('readline-sync'),
products = [];
products[1] = "Drink";
products[2] = "Crisps";
products[3] = "Chocolate";
products[4] = "Candy";

var productPurchase = readlineSync.question('Would you like to purchase a   product? ');
if (productPurchase == "yes") {
    index = readlineSync.keyInSelect(products, 'What product would you like?');
    if (index == [1]) 
        console.log('Thank you, your Drink' + ' has now been dispensed.');
    else if (index == [2]) 
        console.log('Thank you, your Crisps' + ' has now been dispensed.');
    else if (index == [3]) 
        console.log('Thank you, your Chocolate' + ' has now been dispensed.');
    else if (index == [4]) 
        console.log('Thank you, your Candy' + ' has now been dispensed.');
}

Answer 3

您正在嵌套if语句。将它们设置在同一级别。或者，也可以使用if else：

if (index == 1) {
  console.log('Thank you, your Drink' + ' has now been dispensed.');
}
else if (index == 2) {
  console.log('Thank you, your Crisps' + ' has now been dispensed.');
}
else if (index == 3) {
  console.log('Thank you, your Chocolate' + ' has now been dispensed.');
}
else if (index == 4) {
  console.log('Thank you, your Candy' + ' has now been dispensed.');
}

Answer 4

你的花括号搞砸了。你有这样的一个像这样：

if(){
    if(){
        if(){
            if(){
            }
        }
    }
}

尝试将代码更改为：

var readlineSync = require('readline-sync'),
products = [];
products[1] = "Drink";
products[2] = "Crisps";
products[3] = "Chocolate";
products[4] = "Candy";

var productPurchase = readlineSync.question('Would you like to purchase a   product? ');
if (productPurchase == "yes") {
    index = readlineSync.keyInSelect(products, 'What product would you like?');
    if (index == 1) {
        console.log('Thank you, your Drink' + ' has now been dispensed.');
    }
    if (index == 2) {
        console.log('Thank you, your Crisps' + ' has now been dispensed.');
    }
    if (index == 3) {
        console.log('Thank you, your Chocolate' + ' has now been dispensed.');
    }
    if (index == 4) {
        console.log('Thank you, your Candy' + ' has now been dispensed.');
    }

}

使用正确的缩进有助于避免此类问题。如果您的代码编写得更干净，您可能会立即发现问题。

注意：您可能希望将这些if语句更改为switch。这种情况可能是最好的。

使用JS的数组问题

4 个答案: