求助：无法获取API返回对象中各加密货币的USD数值

Hey there! Let's get this sorted for you. The core issue here is that request.responseText returns a JSON string, not a native JavaScript object. You can't directly access nested properties like XRP.USD on a string—so we need to parse it first. Here's how to do it step by step:

Step 1: Parse the JSON String into a JavaScript Object #

First, convert the raw response text into a workable JS object using JSON.parse():

// Your existing response text stored in XRPUSD
let XRPUSD = '{"XRP":{"USD":1.08},"ETH":{"USD":921.49},"BTC":{"USD":11755.04}}';

// Parse the string to an object
const priceData = JSON.parse(XRPUSD);

Step 2: Extract Individual USD Prices #

Now you can access each cryptocurrency's USD value using dot notation (or bracket notation if you prefer):

// Extract XRP's USD price
const xrpUsd = priceData.XRP.USD;
// Or using bracket notation: priceData['XRP']['USD']

// Extract ETH's USD price
const ethUsd = priceData.ETH.USD;

// Extract BTC's USD price
const btcUsd = priceData.BTC.USD;

Step 3: Verify the Results #

Test it out with console.log to confirm you're getting the right values:

console.log("XRP Price (USD):", xrpUsd); // Output: 1.08
console.log("ETH Price (USD):", ethUsd); // Output: 921.49
console.log("BTC Price (USD):", btcUsd); // Output: 11755.04

Bonus: Simplify with Modern Fetch API #

If you're using the modern fetch API instead of an older XMLHttpRequest, you can skip manual parsing entirely by using the .json() method, which automatically converts the response to a JS object:

fetch('https://min-api.cryptocompare.com/data/pricemulti?fsyms=XRP,ETH,BTC&tsyms=USD')
  .then(response => response.json())
  .then(priceData => {
    console.log("XRP:", priceData.XRP.USD);
    console.log("ETH:", priceData.ETH.USD);
    console.log("BTC:", priceData.BTC.USD);
  })
  .catch(error => console.error("Failed to fetch data:", error));

That should resolve your issue—you'll be able to access each cryptocurrency's USD value without any problems now.

内容的提问来源于stack exchange，提问作者Andrew Lee