C Passing Function as Argument

Question

I ve written a function in C  that does a numerical differentiation  It looks like this   public double Diff double x        double h   0 0000001       return  Function x   h  - Function x     h      I would like to be able to pass in any function  as in   public double Diff double x  function f        double h   0 0000001       return  f x   h  - f x     h      I think this is possible with delegates  maybe   but I m not sure how to use them   Any help would be greatly appreciated

User · Answer

public static T Runner lt T gt  Func lt T gt  funcToRun          Do stuff before running function as normal     return funcToRun        Usage   var ReturnValue   Runner      gt  GetUser 99

User · Answer

Using the Func as mentioned above works but there are also delegates that do the same task and also define intent within the naming   public delegate double MyFunction double x    public double Diff double x  MyFunction f        double h   0 0000001       return  f x   h  - f x     h     public double MyFunctionMethod double x           Can add more complicated logic here     return x   10     public void Client         double result   Diff 1 234  x   gt  x   456 1234       double secondResult   Diff 2 345  MyFunctionMethod

User · Answer

There are a couple generic types in  Net  v2 and later  that make passing functions around as delegates very easy   For functions with return types  there is Func lt   and for functions without return types there is Action lt     Both Func and Action can be declared to take from 0 to 4 parameters   For example  Func  lt  double  int   takes one double as a parameter and returns an int   Action  lt  double  double  double   takes three doubles as parameters and returns nothing  void    So you can declare your Diff function to take a Func   public double Diff double x  Func lt double  double gt  f        double h   0 0000001       return  f x   h  - f x     h      And then you call it as so  simply giving it the name of the function that fits the signature of your Func or Action   double result   Diff myValue  Function     You can even write the function in-line with lambda syntax   double result   Diff myValue  d   gt  Math Sqrt d   3 14

[c#] C# Passing Function as Argument

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