如何同步讀取csv文件並使用javascript從中返回值

Question

我通過一個名為findAbbreviation（fullName）的函數傳遞一個完整的州名。我使用全名的csv文件，縮寫對來返回與全名匹配的縮寫值。 考慮到我希望讀取csv是同步的，最好的方法是什么？

d3.csv（“candy.csv”，function（csv）{

//reformat the locations to have a consistent format
//every entry in q5 is changed to an abbreviation of 2 letters
//the abbreviation lists are in the folder named such
var updatedAbbr = csv.map(function(d) {

    //check to see the entry has a value
    if (d.Q5_STATE != null) {

        //the country is the united States
        if (d.Q4_COUNTRY == "United States") {

            //if the state value is longer than two characters, set it to UU
            if (d.Q5_STATE.length > 2) {
                d.Q5_STATE = findAbbreviation(d.Q5_STATE);  
            }

            //pass through and check that the new value is not null
            if (d.Q5_STATE != null) {
                console.log(d.Q5_STATE);    
            }


        }
    }
});

}）;

function findAbbreviation（fullName）{

}

我想傳遞價值阿拉巴馬州並得到AL。 或加利福尼亞州 - > CA.

Answer 1

d3.csv是異步的，你無法做任何事情。

您可以使用XMLHttpRequest發出同步請求（ 危險 ：不推薦使用此功能），然后通過d3.csv.parse提供結果。

我建議改為使用異步編程。