如何从source、destination和prices数组中获取指定路线的价格？

嘿，这事儿其实挺简单的，咱们只需要遍历数组，找到**出发地等于src且目的地等于des**的索引位置，然后取出对应prices数组里的值就行。下面给你几种常用的实现方式，都是JavaScript的写法：

方法一：普通for循环（最直观） #

这种方式适合新手理解，逐一遍历每个索引，匹配条件后就拿到目标价格：

const source = ["hyderabd","banglore","hyderabad","chennai","pune","mumbai"];
const destination = ["pune","chennai","mumbai","hyderabad","banglore","hyderabad"];
const prices = ["500","300","400","600","500","500"];
const src = "hyderabad";
const des = "mumbai";

let targetPrice = null;
// 遍历数组每个元素的索引
for (let i = 0; i < source.length; i++) {
  // 同时匹配出发地和目的地
  if (source[i] === src && destination[i] === des) {
    targetPrice = prices[i];
    break; // 找到第一个匹配项就停止遍历，提升效率
  }
}

console.log(targetPrice); // 输出："400"

方法二：使用数组findIndex方法（更简洁） #

利用findIndex直接找到符合条件的索引，再通过索引取价格：

const source = ["hyderabd","banglore","hyderabad","chennai","pune","mumbai"];
const destination = ["pune","chennai","mumbai","hyderabad","banglore","hyderabad"];
const prices = ["500","300","400","600","500","500"];
const src = "hyderabad";
const des = "mumbai";

// 找到符合条件的索引
const matchIndex = source.findIndex((city, index) => 
  city === src && destination[index] === des
);
// 通过索引获取对应价格
const targetPrice = prices[matchIndex];

console.log(targetPrice); // 输出："400"

方法三：使用forEach遍历 #

通过forEach遍历每个元素，匹配条件后记录价格：

const source = ["hyderabd","banglore","hyderabad","chennai","pune","mumbai"];
const destination = ["pune","chennai","mumbai","hyderabad","banglore","hyderabad"];
const prices = ["500","300","400","600","500","500"];
const src = "hyderabad";
const des = "mumbai";

let targetPrice = null;
source.forEach((city, index) => {
  if (city === src && destination[index] === des) {
    targetPrice = prices[index];
  }
});

console.log(targetPrice); // 输出："400"

小提示： #

注意看你source数组里的第一个元素是"hyderabd"（少了一个字母a），和你的src值"hyderabad"不匹配，所以不会被选中；第三个元素才是正确拼写的"hyderabad"，刚好对应目的地"mumbai"和价格"400"，所以能准确拿到结果。

内容的提问来源于stack exchange，提问作者swetha