我想用JavaScript获取5天的天气预报。
当我执行下面的代码时，我得到：
TypeError: Cannot read property 'temp' of undefined
如果我将https://api.openweathermap.org/data/2.5/forecast?q=更改为：
https://api.openweathermap.org/data/2.5/weather?q=
我准确无误地了解当前天气。
为什么预测在我的情况下不起作用？我是不是错过了什么？
JavaScript(我想.then(data =>代码段中有问题)：
var activities = document.getElementById('activitySelector');
var main = document.querySelector('#name');
var temp = document.querySelector('.temp');
var desc = document.querySelector('.desc');
activities.addEventListener('change', (e) => {
fetch('https://api.openweathermap.org/data/2.5/forecast?q='
+ e.target.value+'&appid=<<<<APIKEY>>>>&cnt=5')
.then(response => response.json())
.then(data => {
var tempValue = data['main']['temp'];
var nameValue = data['name'];
var descValue = data['weather'][0]['description'];
main.innerHTML = nameValue;
desc.innerHTML = "Desc - "+descValue;
temp.innerHTML = "Temp - "+tempValue;
})
.catch(err => alert(err));
})
HTML:
<select name="cities" id="activitySelector">
<div class="options">
<option class="option" value="warsaw">Warsaw</option>
<option class="option" value="phoenix">Phoenix</option>
<option class="option" value="berlin">Berlin</option>
</div>
</select>
<div class="container">
<div class="card">
<h1 class="name" id="name"></h1>
<p class="temp"></p>
<p class="clouds"></p>
<p class="desc"></p>
</div>
</div>
我正在尝试获取的JSON：
{"cod"："200"，"message"：0，"cnt"：5，"list"：[{"dt"：1618606800，"main"：{"temp"：279.45，"feels_like"：277.97，"temp_min"：278.72，"temp_max"：279.45，"压力"：1031，"海平面"：1032，"湿度"：56，"温度kf"：0.73}，"；天气"：[{"id"：802，"main"："Clouds"，"description"："scattered"云"图标"："03n"}]"云"：{"全部"：25}；"风"：{"速度"：2.06，"度"：80，"阵风"：6.1}；可见性"：10000；pop"：0；sys"：{"pod"："n"}；dt_txt"："2021-04-16 21:00:00"}，{"dt"：1618617600，"main"：{"temp"：278.63，"feels_like"：277.46，"temp_min"：276.98，"temp_max"：278.93，"pressure"：1031，"sea_level"：2051，"grnd_level temp_kf"：1.65}，"；天气"：[{"id"：801，"main"："Clouds"，"description"："near"云"图标"："02n"}]"云"：{"全部"：23}，"；"风"：{"速度"：1.65，"度"：53，"阵风"：4.49}；可见性"：10000；pop"：0；sys"：{"pod"："n"}；dt_txt"："2021-04-1700:00:00"}，{"dt"：1618628400，"main"：{"temp"：276.91，"feels_like"：275.48，"temp_min"：275.64，"temp_max"：276.901，"pressure"：1031，"sea_level"：2051，"grnd_level temp_kf"：1.27}，"；天气"：[{"id"：800，"main"："Clear"，"description"："Clear天空"图标"："01n"}]"云"：{"全部"：10}，"；"风"：{"速度"：1.65，"度"：21，"阵风"：4.06}；可见性"：10000；pop"：0；sys"：{"pod"："n"}；dt_txt"："2021-04-1703:00:00〃}，{"dt"：1618639200，"main"：{"temp"：275.25，"feels_like"：273.27，"temp_min"：275.25'，"temp_max"：275.25，"pressure"：1031，"sea_level"：2051，"grnd_level"：1028，"湿度"：67，"temp_kf"0｝；天气"：[{"id"：800，"main"："Clear"，"description"："Clear天空"图标"："01d"}]"云"：{"all"：1}；"风"：{"速度"：1.89，"度"：16，"阵风"：4.72}；可见性"：10000；pop"：0；sys"：{"pod"："d"}；dt_txt"："2021-04-1706:00:00〃}，{"dt"：1618650000，"main"：{"temp"：280.37，"feels_like"：278.43，"temp_min"：280.357，"temp_max"：280.3.7，"pressure"：1030，"sea_level"：1030，"grnd_level"：1027，"湿度"：44，"temp _kf"：0}，"；天气"：[{"id"：800，"main"："Clear"，"description"："Clear天空"图标"："01d"}]"云"：{"all"：2}；"风"：{"速度"：2.84，"度"：39，"阵风"：4.51}；可见性"：10000；pop"：0；sys"：{"pod"："d"}；dt_txt"："2021-04-1709:00:00"}]"城市"：{"id"：2643743，"name"："London"，"coord"：{"lat"：51.5085，"lon"：-0.1257}；country"："GB""群体"：1000000，"；"时区"：3600；日出"：1618549331；日落"：1618599475｝｝
问题只是取消引用所需值的方式。
CCD_ 4具有属性CCD_。list是一个对象数组，每个对象都有一个main键，该键指向一个具有temp键的对象。
例如，您可以抓取所有元素并记录它们的main.temp字段，如下所示：
const data = {
"cod": "200",
"message": 0,
"cnt": 5,
"list": [{
"dt": 1618606800,
"main": {
"temp": 279.45,
"feels_like": 277.97,
"temp_min": 278.72,
"temp_max": 279.45,
"pressure": 1031,
"sea_level": 1031,
"grnd_level": 1028,
"humidity": 56,
"temp_kf": 0.73
},
"weather": [{
"id": 802,
"main": "Clouds",
"description": "scattered clouds",
"icon": "03n"
}],
"clouds": {
"all": 25
},
"wind": {
"speed": 2.06,
"deg": 80,
"gust": 6.1
},
"visibility": 10000,
"pop": 0,
"sys": {
"pod": "n"
},
"dt_txt": "2021-04-16 21:00:00"
}, {
"dt": 1618617600,
"main": {
"temp": 278.63,
"feels_like": 277.46,
"temp_min": 276.98,
"temp_max": 278.63,
"pressure": 1031,
"sea_level": 1031,
"grnd_level": 1028,
"humidity": 61,
"temp_kf": 1.65
},
"weather": [{
"id": 801,
"main": "Clouds",
"description": "few clouds",
"icon": "02n"
}],
"clouds": {
"all": 23
},
"wind": {
"speed": 1.65,
"deg": 53,
"gust": 4.49
},
"visibility": 10000,
"pop": 0,
"sys": {
"pod": "n"
},
"dt_txt": "2021-04-17 00:00:00"
}, {
"dt": 1618628400,
"main": {
"temp": 276.91,
"feels_like": 275.48,
"temp_min": 275.64,
"temp_max": 276.91,
"pressure": 1031,
"sea_level": 1031,
"grnd_level": 1027,
"humidity": 66,
"temp_kf": 1.27
},
"weather": [{
"id": 800,
"main": "Clear",
"description": "clear sky",
"icon": "01n"
}],
"clouds": {
"all": 10
},
"wind": {
"speed": 1.65,
"deg": 21,
"gust": 4.06
},
"visibility": 10000,
"pop": 0,
"sys": {
"pod": "n"
},
"dt_txt": "2021-04-17 03:00:00"
}, {
"dt": 1618639200,
"main": {
"temp": 275.25,
"feels_like": 273.27,
"temp_min": 275.25,
"temp_max": 275.25,
"pressure": 1031,
"sea_level": 1031,
"grnd_level": 1028,
"humidity": 67,
"temp_kf": 0
},
"weather": [{
"id": 800,
"main": "Clear",
"description": "clear sky",
"icon": "01d"
}],
"clouds": {
"all": 1
},
"wind": {
"speed": 1.89,
"deg": 16,
"gust": 4.72
},
"visibility": 10000,
"pop": 0,
"sys": {
"pod": "d"
},
"dt_txt": "2021-04-17 06:00:00"
}, {
"dt": 1618650000,
"main": {
"temp": 280.37,
"feels_like": 278.43,
"temp_min": 280.37,
"temp_max": 280.37,
"pressure": 1030,
"sea_level": 1030,
"grnd_level": 1027,
"humidity": 44,
"temp_kf": 0
},
"weather": [{
"id": 800,
"main": "Clear",
"description": "clear sky",
"icon": "01d"
}],
"clouds": {
"all": 2
},
"wind": {
"speed": 2.84,
"deg": 39,
"gust": 4.51
},
"visibility": 10000,
"pop": 0,
"sys": {
"pod": "d"
},
"dt_txt": "2021-04-17 09:00:00"
}],
"city": {
"id": 2643743,
"name": "London",
"coord": {
"lat": 51.5085,
"lon": -0.1257
},
"country": "GB",
"population": 1000000,
"timezone": 3600,
"sunrise": 1618549331,
"sunset": 1618599475
}
}
for (const day of data.list){
console.log(`Temp: ${day.main.temp}`)
}所以你有
https://api.openweathermap.org/data/2.5/forecast?q=
在文档中我看到
api.openweathermap.org/data/2.5/forecast/daily?q={city name}&cnt={cnt}&appid={API key}
所以我认为你的URL中每天都缺少/。