Question

我有天气值为List<Weather> weatherList = new ArrayList();的对象列表

在列表上，我有两个对象：

{
    "latitude": 13.699444,
    "longitude": 12.676667,
    "timezone": "",
    "daily": {
        "data": [
            {
                "time": 1586037600,
                "sunriseTime": 1586059620,
                "sunsetTime": 1586107860,
                "moonPhase": 0.41,
                "temperatureHigh": 8.36,
                "temperatureHighError": 3.58,
                "temperatureLow": 3.72,

            }
        ]
    },
    "offset": 2
}

和

{
    "latitude": 11.699444,
    "longitude": 10.676667,
    "timezone": "",
    "daily": {
        "data": [
            {
                "time": 1586037600,
                "sunriseTime": 1586059620,
                "sunsetTime": 1586107860,
                "moonPhase": 0.41,
                "temperatureHigh": 12.36,
                "temperatureHighError": 6.58,
                "temperatureLow": 3.72,

            }
        ]
    },
    "offset": 2
}

我当然有所有的获取器和设置器。我需要拾取具有较大值（temperatureHigh / temperatureLow）/ 2的该对象。我尝试过

Double resultNumber;
for(Weather weather:  weatherList){
     resultNumber = ((weather.getDaily().getData().get(0).getTemperatureLow()/weather.getDaily().getData().get(0).getTemperatureHigh())/2);
//and here I got result for only one object
}

我应该怎么做？我应该补充说：Map<resultNumber,WeatherObject>吗？得到我的价值？还是可以选择在此处使用流和lambda？

Answer 1

您可以只声明另一个存储当前值（temperatureHigh / temperatureLow）/ 2的变量。然后，将其与您存储的resultNumber进行比较。如果此临时数字较大，则将resultNumber和resultWeather都更新为当前值和天气。

Double temp;
Double resultNumber; 
Weather resultWeather; 
for(Weather weather:  weatherList){
    temp = ((weather.getDaily().getData().get(0).getTemperatureLow()/weather.getDaily().getData().get(0).getTemperatureHigh())/2);
    if(resultNumber == null || Double.compare(resultNumber,temp) < 0) {
        resultNumber = temp;
        resultWeather = weather;
    }
}
//at this point resultWeather holds the weather with the highest value

或者如果weatherList中只有两个天气，则可以只执行if else语句来比较两个天气的值，然后将较大值的天气存储到另一个天气对象中。

double value1 = weatherList.get(0).(the operation to get the value for the first weather);
double value2 = weatherList.get(1).(the operation to get the value for the other weather);
Weather resultWeather;
if(value1 > value2){
    resultWeather = weatherList.get(0);
}
else{
    resultWeather = weatherList.get(1);
}
//at this point resultWeather holds the weather with the higher value of the two

如何对对象属性进行数学运算？

1 个答案: