如何在C＃中一次初始化多个对象

Question

I need to initialize multiple objects like this.

DataTable dt1 = new DataTable();
DataTable dt2 = new DataTable();
DataTable dt3 = new DataTable();
DataTable dt4 = new DataTable();

Is there a way to initialize them as

DataTable dt1, dt2, dt3, dt4 = new DataTable();

If I use above, there are no compile errors but there are runtime errors says An Object reference not set to an instance.

How can I achieve this.

Answer 1

No, there´s no such way, you have to initialize them one by one.

Your error appears because dt1 to dt3 are initialized to null , only dt4 has a value. Thus doing anything with d1 will throw a NullReferenceException .

But you can do so in a single line:

DataTable t1 = new DataTable(), t2 = new DataTable(), t3 = new DataTable(), t4 = new DataTable();

Even better would be a list/array:

var tables = new[] { new DataTable(), new DataTdable(), new DataTable(), new DataTable() };

or even

var tables = Enumerable.Range(0, 4).Select(x => new DataTable());