How to check whether string has been assigned a value or not?

Answer:

With the help of IsNullOrEmpty method of string,we can check whether string has a value or not.It returns True or False.
Basically IsNullOrEmpty checks whether string contains value or not.

For Example:-

string str = null;



if(string.IsNullOrEmpty(str))

  MessageBox.Show('value is null');

else 

  MessageBox.Show('value is not null');

Output would be 'value is null' because str varaible has not assigned any value.