Default value List for different data type in C#

In C# there are different data type and they use some default value when we declare a variable. When we define a variable of type int or Int32 say int score; so what is the value of score, will it be null or zero, in the same way if we create a variable of type string/String what value it holds by default. I was working on a project and used following code

int score; If (somecondition == true) score = somevalue; 

And I was expecting if condition is true then score will be assigned otherwise it would be null but I was wrong because default value for an int variable is zero (0). Finally I changed my code, and forcibly make my score variable to nullable.

Int? score; If (somecondition == true) score = somevalue; 

On the other hand String is by default null and not an empty string also string not a value type in C# but its a reference type.

Here is the some mostly used data type and their default values

 DATE TYPE  |  DEFAULT VALIE
------------------------------------
 String     |  null
 bool       |  false
 char       |  '\0'
 decimal    |  0.0M
 double     |  0.0D
 enum       | The value produced by the expression (E)0,
                      where E is the enum identifier.
 float      |  0.0F
 int        |  0
 long       |  0L
 sbyte      |  0
 short      |  0
 struct     |  The value produced by setting all value-type fields to their 
                   default values and all reference-type fields to null.
 uint       |  0
 ulong      |  0
 ushort     |  0