OpenWeather API 未使用 Javascript 连接

如何解决OpenWeather API 未使用 Javascript 连接

我想显示我输入的州的天气状况，但它一直提示“错误的城市名称，然后显示未定义

var button =document.querySelector('.button')
var inputValue =document.querySelector('.inputValue')
var nam =document.querySelector('.nam');
var desc =document.querySelector('.desc');
var temp =document.querySelector('.temp');


button.addEventListener('click',function(){
    fetch('https://api.openweathermap.org/data/2.5/weather?q='+inputValue.value+'&appid=0c712e338cabb3996a78ae788fa566a1')
    .then(response=> response.json())
    .then(data => {
        var nameValue = data['nam'];
        var temp = data['main']['temp'];
        var descValue = data['weather'][0]['description'];
        nam.innerHTML =nameValue;
        temp.innerHTML =tempValue;
        desc.innerHTML =description;
    })
    .catch(err => alert("Wrong City name!"))
    
    })

解决方法

如果您从 API [1] 收到错误响应，那么由于嵌套结构，您将在以下行的代码中抛出一些异常。

// "main" does not exist in error response,so you 
// will get an error trying to access a child of "main".
var temp = data['main']['temp'];

// "weather" does not exist in error response,so you
// will get an error trying to access a child of "weather".
var descValue = data['weather'][0]['description'];

在尝试解析响应数据之前检查响应代码是一个好习惯，就像这样 -

.then(response => {
  if (response.cod == 200) {
    // Do your stuff
  } else {
    throw new Error(response.message)
  }
).catch(err => alert(err))

除此之外，您的代码中还有几个拼写错误 -

// There is no key "nam" in the response,it is "name",see success response [2].
var nameValue = data['nam'];

// You save the description as "descValue"
var descValue = data['weather'][0]['description'];
// But use "description" here
desc.innerHTML =description;

[1] 错误响应 -

{
  "cod": "404","message": "city not found"
}

[2] 成功响应（如果城市存在）-

{
  "coord": {...},"weather": [...],"base": "stations","main": {...},"visibility": 10000,"wind": {...},"clouds": {...},"dt": 1618812226,"sys": {...},"timezone": -14400,"id": 4350049,"name": "California","cod": 200
}