//app.js
const SEARCH_VIEW = document.getElementById('search_view');
const RESULTS_VIEW = document.getElementById('results_view');
const FORECAST_VIEW = document.getElementById('forecast_view')
function loadCities(){
const cities = ["London", "Paris", "Madrid", "Lisbon","Ohrid"];
var options = null;
var dest = document.getElementById('dest');
//Looping the cities
cities.forEach(city => {
options += '<option>' + city +'</options>';
});
dest.innerHTML = options;
}
function gettingWeather(){
// 1. Open the Url
var dest = document.getElementById('dest').value;
var url = ('http://api.openweathermap.org/data/2.5/weather?q='+ dest + '&appid=exampleAppId');
console.log(url);
console.log(dest);
// 2. Fetch the URL
fetch(url)
.then(response => {
if(response.status !== 200){
console.error("API failed, Status Code " + response.status);
return;
}
console.log(response);
// 3.We make the response .json and open the data
response.json().then(data => {
console.log(data);
RESULTS_VIEW.style.visibility = 'visible';
// Temperature
document.getElementById('Temperature').textContent = data.main.temp;
//Wind
document.querySelector('.Wind').textContent = data.wind.speed * data.wind.deg;
//Description
document.querySelector('.Description').textContent = data.weather[0].description;
});
}).catch(err => {
console.error("Fetch error "+ err);
});
}
function forecast(){
const API_BASE = 'http://api.openweathermap.org/data/2.5/forecast?mode=json&';
const API_KEY = 'appid=exampleAppId&';
var dest = document.getElementById('dest').value;
var url = API_BASE + API_KEY + 'q=' + dest.value;
console.log(url);
console.log(dest.value);
// 2. Fetch the URL
fetch(url)
.then(response => {
if(response.status !== 200){
console.error("API failed, Status Code " + response.status);
return;
}
console.log(response);
// 3.We make the response .json and open the data
response.json().then(data => {
console.log(data);
RESULTS_VIEW.style.visibility = 'hidden';
FORECAST_VIEW.style.visibility= 'visible';
});
}).catch(err => {
console.error("Fetch error "+ err);
});
}
index.html
<!DOCTYPE html>
<html>
<head>
<title>Weather App</title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width ,initial-scale=1">
<link href="styles.css" type="text/css" rel="stylesheet">
</head>
<body onload="loadCities();">
<div class="container">
<div id = "results_view">
<div class="inputWrapper">
<h1> Weather App </h1>
<p>Choose a city.</p>
<select id="dest" onchange="gettingWeather();" width=150 style="width:150px" ></select><br>
<label>Temperature</label>
<label class="Temperature" id="Temperature"></label><br>
<label>Wind</label>
<label class="Wind" id="Wind"></label><br>
<label>Description</label>
<h1 class="Description" id="Description"></h1>
<button onclick="forecast();">Forecast</button>
</div><!-- InputWrapper -->
</div>
<div id="forecast_view">
<h1>ForeCast</h1>
</div>
</div> <!-- end container -->
<script src="app.js"></script>
</body>
</html>
我的任务是选择随机的5个欧洲城市并显示一些属性，但是当点击按钮时，我需要显示该城市的预测。我尝试使用词法范围，我的一半应用程序工作简单的部分，我显示从API获取的一些属性，当我点击按钮预测我有错误的响应错误，但错误也是我选择的城市。如果我使用任何城市，在预测中是未定义的。我不知道为什么我有这个错误，我没有任何内部尝试关闭如果你不知道任何答案我会很感激即使是一个洞察或类似的工作参考。
谢谢
问题是你的变量“dest”已经包含了这个值。所以你在“dest”中有你的城市的名字，你使用未定义的dest.value，因为dest是一个字符串，没有名为value的属性。修复你的代码只需删除网址中的.value：
const API_BASE = 'http://api.openweathermap.org/data/2.5/forecast?mode=json&';
const API_KEY = 'appid=6c345b20d0c8fac21a36761eb7d6cd38&';
var dest = document.getElementById('dest').value;
var url = API_BASE + API_KEY + 'q=' + dest; // only dest NOT dest.value
console.log(dest); // the city selected