What is params keyword in C# ?

The params keyword lets you specify a method parameter that takes a variable number of arguments.

No additional parameters are permitted after the params keyword in a method declaration, and only one params keyword is permitted in a method declaration.

You can send a comma-separated list of arguments of the type specified in the parameter declaration, or an array of arguments of the specified type. You also can send no arguments

Example :
public static void UseParams(params int[] list)
{
for (int i = 0; i < list.Length; i++)
{
Console.Write(list[i] + " ");
}
Console.WriteLine();
}
We can call above method

Way 1 :
// You can send a comma-separated list of arguments of the specified type.
UseParams(1, 2, 3, 4);

Way 2 :
// An array argument can be passed, as long as the array
// type matches the parameter type of the method being called.

int[] myIntArray = { 5, 6, 7, 8, 9 };
UseParams(myIntArray);

Way 3:
UseParams();