javascript - 需要帮助访问 JSON 数组对象

Question

目标:此代码收集 JSONAPIS 数组并将 APIS 传递到 $.each() 循环中。然后在 if 语句中评估 JSON 数据字段并用于计算 precip。如何从 obj.json 访问 JSONAPIS主要问题:每日数组成员上未定义 obj.daily.data.length。该 obj 应包含 API 调用之一和要使用的 JSON 数据集。相反，它包含像 abort、always、promise 这样的关键字，我不熟悉如何使用。什么会访问结果 JSON 对象属性？

var listAPIs = "";
var darkForecastAPI = [];
var result = [];
var JSONAPIS = [];

$.each(numDaysAPITimes, function(a, time) {
    var darkForecastAPI = /*"http://api.wunderground.com/api/" + currentAPIKey + "/history_" + time + "/q/" + state + "/" + city +".json?callback=?"; */
        "http://api.forecast.io/forecast/" + currentAPIKey + "/" + city + time + "?callback=?";
    //https://api.forecast.io/forecast/APIKEY/LATITUDE,LONGITUDE,TIME
    JSONAPIS.push($.getJSON(darkForecastAPI, {
        tags: "WxAPI[" + i + "]", //Is this tag the name of each JSON page? I tried to index it incase this is how to refer to the JSON formatted code from the APIs.
        tagmode: "any",
        format: "json"
    }));
});
$.when.apply($, JSONAPIS).done(function(result) { /*no log simply an array */
    var eachPrecipSum = 0.0;
    var totalPrecipSinceDate = 0.0;
    alert(result);

    $.each(result, function(d, obj) {
    console.log(obj);
        for (var c = 0; c <= obj.daily.data.length - 1; c++) {
            if (obj.daily.data[c].precipIntensity >= 0.0000 && obj.daily.data[c].precipType == "rain") /*Number(result.history.dailysummary.precipm, result.history.dailysummary.rain*/ {
                eachPrecipSum = result[d].daily.data[c].precipIntensity;
                totalPrecipSinceDate = eachPrecipSum + totalPrecipSinceDate; ///Write mean precip
                alert(Math.round(eachPrecipSum * 10000) / 10000);
                $("body").append("p").text("There has been as least a total of " + Math.round(totalPrecipSinceDate * 10000) / 10000 + " inches per hour of rain at the location in the last " + userDataDatePick + " days")

            } else if (obj.daily.data[c].precipIntensity >= 0.0000 && obj.daily.data[c].precipType != "rain") {
                alert("There is was no rain on ____" /*+ result.history.dailysummary.mon + "/" + result.history.dailysummary.mday + "/" + result.history.dailysummary.year*/ );
            }
        }
    });
});
numDaysAPITimes = 0;

}

Answer 1

$.when 不将数组作为输入

由于您传递的数组本身不是一个 promise ，因此它可能会立即触发，因此在所有 ajax 调用完成之前

需要更改为

$.when.apply(null, JSONAPIS).done...