TypeError：无法读取属性＆＃39; name＆＃39;在节点js代码中未定义

Question

如果条件columnName ==＆＃39; name＆＃39;

，我收到错误

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

此处receivedValues变量似乎未定义，您应该添加更多代码进行提问。

Answer 2

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

您需要检查 receivedValues 是否存在

您可以优化代码：

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