Question

There is no argument given that corresponds to the required formal parameter 'value' of 'string.isnullorwhitespace(string?)'

Answer 1

This error message indicates that you are trying to call the isnullorwhitespace method of the string class, but you have not provided a value for the required value parameter.

Here is an example of how to properly call the isnullorwhitespace method:

string input = " ";

bool isNullOrWhiteSpace = string.IsNullOrWhiteSpace(input);

The IsNullOrWhiteSpace method returns true if the input string is null, an empty string, or consists only of white space characters.

Step-by-step explanation: