The modifiers used to define an array of parameters or list of arguments is __________refoutparamvar

The modifiers used to define an array of parameters or list of arguments in C# are ref, out, param, and var.

1. ref: This keyword causes arguments to be passed by reference. The effect is that any change to the parameter in the method is reflected in the underlying argument variable in the calling method.

2. out: Similar to ref, the out keyword also causes arguments to be passed by reference. However, out does not require that the variable being passed in is initialized before it is passed to an out parameter.

3. params: This keyword allows for a method to accept a variable number of arguments. The parameter type must be a single-dimensional array.

4. var: This keyword is used to declare an implicitly typed local variable. It tells the compiler to figure out the type of the variable at compile time. However, it's not a modifier for method parameters.