Why we are using {0}???

Answer 1

{0} is refer to first index number
{1} is refer to second index number and so on.

example:

int x = 5;
double y = 6.8;
int z = 7;
Console.WriteLine("numbers are {0} and {2}", x,y,z) ;
/*the output is :
numbers are 5 and 7*/

Answer 2

This is for printing a formatted string.
For exmple:

String.Format(“This {0} an example.“, “is“);
//output
This is an example.

You can store variables in there too like:

string text = “is“;
Console.WriteLine(“This {0} an example.“, text);

Answer 3

Got it
thanks a lot :)