javascript - 使用JS的数组问题

Question

我目前正在使用节点/终端开发一台简单的产品机器，但我遇到了一个问题。我添加了一个数组，其中包含与元素相关的编号 ID。我正在使用 readline 询问用户想要什么产品。

当输入 ID 1 时，它会提供饮料成功的消息。但是当输入 2、3 或 4 时，没有任何反应？

谁能看出我在这里做错了什么，我将不胜感激!

亲切的问候!

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.');

}}}}}

Answer 1

您嵌套的 if 永远不会被执行，index 不能同时为 1 和 3。我建议您改用 switch ，这基本上就是您要尝试做的事情:

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:已更正 index 的错误用法。 keyInSelect()将索引作为数字而不是数组返回。