原生js实现查询天气小应用

 //调用jsonp函数请求当前所在城市
jsonp('https://api.map.baidu.com/api"img")[0];
 var firstWeatherId=data.result.data.realtime.weather.img;
 chooseImg(firstWeatherId,firstImg);

 var aImg = document.getElementById('future_container').getElementsByTagName('img');
 for(var j=0; j<aImg.length; j++){
  var weatherId = data.result.data.weather[j].info.day[0];
  chooseImg(weatherId,aImg[j]);
 }
}
//选择图片
function chooseImg(id,index){
 switch(id){
  case '0':
   index.src='images/weather_icon/1.png';
   break;
  case '1':
   index.src='images/weather_icon/2.png';
   break;
  case '2':
   index.src='images/weather_icon/3.png';
   break;
  case '3':
  case '7':
  case '8':
   index.src='images/weather_icon/4.png';
   break;
  case '6':
   index.src='images/weather_icon/6.png';
   break;
  case '13':
  case '14':
  case '15':
  case '16':
   index.src='images/weather_icon/5.png';
   break;
  case '33':
   index.src='images/weather_icon/7.png';
   break;
  default:
   index.src='images/weather_icon/8.png';
 }
}
//根据城市名创建请求数据及url
function createUrl(){
 var cityName = '';
 if(arguments.length == 0) {
  cityName = document.getElementById('text').value;
 }else{
  cityName = arguments[0];
 }
 var url = 'https://op.juhe.cn/onebox/weather/query?cityname=' + encodeURI(cityName) + '&key=1053d001421b886dcecf81a38422a1a2&callback=getWeather';
 return url;
}