如何在以下情况下使用三元运算符？ [英] How to use ternary operator in my following case?

问题描述

Hii，





objEmployeeAbsence.SunWorkingHour = dtProperRecord.Rows [i] [SunWorkingHour]。ToString（）== || dtProperRecord.Rows [i] [SunWorkingHour]。ToString（）==0？ null：上面代码中的Math.Round（float.Parse（dtProperRecord.Rows [i] [SunWorkingHour]。ToString（）），2）;



=> objEmployeeAbsence.SunWorkingHour中包含双数据类型。所以当我使用上面的类型条件时..如果它是真的，则不会设置null。如果我在那里使用0然后它取而不是空的





同时..如果我尝试使用if else块并尝试在objEmployeeAbsence.SunWorkingHour中指定null它被赋值..



这里是if else的代码

Hii ,


objEmployeeAbsence.SunWorkingHour = dtProperRecord.Rows[i]["SunWorkingHour"].ToString() == "" || dtProperRecord.Rows[i]["SunWorkingHour"].ToString() == "0" ? null : Math.Round(float.Parse(dtProperRecord.Rows[i]["SunWorkingHour"].ToString()), 2);

in the above code=> objEmployeeAbsence.SunWorkingHour has double datatype in it. so when i use above type condition .. null is not get set in it if its true. if i use 0 there then its taking but not the null


at the same time .. if i try to use if else block and try to assign null in objEmployeeAbsence.SunWorkingHour it gets assign ..

here is the code of if else

if (dtProperRecord.Rows[i]["SunWorkingHour"].ToString() == "" || dtProperRecord.Rows[i]["SunWorkingHour"].ToString() == "0")
                                        {
                                            objEmployeeAbsence.SunWorkingHour = null;
                                        }
                                        else
                                        {
                                            objEmployeeAbsence.SunWorkingHour = Math.Round(float.Parse(dtProperRecord.Rows[i]["SunWorkingHour"].ToString()), 2);
                                        }

我怎样才能做到这一点使用三元可能赋值null

how can i make this possible using ternary possible to assign null

推荐答案

Double是一个值类型（不是引用类型），因此在任何情况下都不能为它赋值。因为Match.Round返回一个double，所以整个三元表达式必须返回一个double，这意味着你不能使用null作为其中一个值。



相反，抛出null以及适当类型的objEmployeeAbsence.SunWorkingHour的双倍，无论声明为什么 - 它似乎有一个隐式转换可用，因此显式转换应该可以正常工作。

Double is a value type (not a reference type) so you cannot assign a null to it under any circumstances. Because Match.Round returns a double the whole ternary expression must return a double which means you can't use null as one of the values.

Instead, cast the null and the double to the appropriate type of objEmployeeAbsence.SunWorkingHour, whatever that is declared as - it appears there is an implicit conversion available, so an explicit cast should work fine.

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