CODEWITHSUNDEEP
c#
bilal
bilal

Reputation: 658

Why the behavior of Convert.ToString(object as null) vs Convert.ToString(string as null)

I have created a console application to analyze the behavior of 

Convert.ToString()

, i know Convert.ToString() do not cause exception, but in terms of object it initialize the return string as empty, however in case of string it remains null.

string s = null;
object obj = null;
string objec = Convert.ToString(obj);//it return an empty string
string ss = Convert.ToString(s);// it returns ss=null

Upvotes: 1

Views: 108

Answers (1)

Usman
Usman

Reputation: 4703

When you look at their compiled assemblies the program looks like this

        string s = null;
        Convert.ToString(null); //1
        Convert.ToString(s);  // 2

the first ToString Returns "" string because it checks the following condition

         if (value == null)
        {
            return string.Empty;
        }

and the second ToString returns null because it executes following method

 public static string ToString(string value)
        {
            return value;
        }

it looks confusing because ToString is same on both statements but actually they both are working differently. The first ToString function calls the ToSting of Object Type and the second ToString function calls ToString of String Type

Upvotes: 2

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