javascript - JS 警报或追加在 DOM 上不起作用

Question

请查看 https://jsfiddle.net/safron6/9g98j68g/embedded/result/ 上的此代码

我试图从生成的 APIS 和 JSON 代码列表中获取计算结果，以显示 precipIntensity。在代码末尾有一个警报，代码可以在 firebug 中运行，但没有显示任何内容。不弹出警报的原因可能是什么？

var listAPIs = "";

$.each(threeDayAPITimes, function(i, time) {
    var darkForecastAPI= "https://api.forecast.io/forecast/" + currentAPIKey + "/" + locations + "," + time +"?callback=?"; 
     $.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"
    }, function(result) {
        // Process the result object    
        var eachPrecipSum = 0;
    if(result.currently.precipIntensity >=0 && result.currently.precipType == "rain")
        {
            $.each(result, function() {
              eachPrecipSum += (result.currently.precipIntensity);
              totalPrecipSinceDate += eachPrecipSum ;  ///Write mean precip
                        alert(eachPrecipSum );
                        $("body").append("p").text(eachPrecipSum)
        });

        }   
    });

Answer 1

totalPrecipSinceDate 未声明。