TypeError：無法讀取節點js代碼中未定義的屬性“名稱”

Question

如果條件columnName =='name'，我得到了錯誤

receivedValues = req.body
var usercolumns = ["name","price","duration","gender"];

    //FOR VALIDATING VALUES BEFORE SUBMISSION
    for(var iter=0;iter<usercolumns.length;iter++)

    {
        columnName = usercolumns[iter];
        console.log("column name",columnName);
        if(receivedValues[columnName] == undefined && (columnName=='name' || columnName=='price' || columnName=='duration' || columnName=='gender'))
        {

Answer 1

您的receivedValues變量在這里似乎未定義，您應該添加更多代碼來提問。

Answer 2

if(receivedValues && receivedValues[columnName] == undefined && (columnName=='name' || columnName=='price' || columnName=='duration' || columnName=='gender'))

您需要檢查是否存在receivedValues

您可以優化代碼：

if(receivedValues && !columnName in receivedValues && columnName in usercolumns)