Making an array of function pointers [duplicate] - c++

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How define an array of function pointers in C
(5 answers)
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My problem is: I want to write a program which create an array function pointers. I know how to make pointer to function, but don't know how to make array of them.
This is what I tried up to now:
double add(double a, double b) { return a + b; }
double sub(double a, double b) { return a - b; }
double mult(double a, double b) { return a * b; }
double div(double a, double b) { return a/b; }
int main() {
double(*Padd)(double a, double b);
double(*Psub)(double a, double b);
double(*Pmult)(double a, double b);
double(*Pdiv)(double a, double b);
Padd = &add;
Psub = ⊂
Pmult = &mult;
Pdiv = ÷
}
In my code I create these pointers to functions in an array like e.g.
double Tpointers[3];
Tpointers[0] = Padd;
Tpointers[1] = Psub;
Tpointers[2] = Pmult;
Tpointers[3] = Pdiv;
How do I do this?

Answer 1

Simply declare a new type 'Tpointers' that represent a pointer to a function that give two double and return a double.
And in the code you can create an array of functions.
#include<iostream>
// The function pointer type!
typedef double (*Tpointers)(double, double);
double add(double a, double b) { return a + b; }
double sub(double a, double b) { return a - b; }
double mult(double a, double b) { return a * b; }
double div(double a, double b) { return a / b; }
int main() {
// A functions pointers array .
Tpointers fun_array[4];
// Assign the values
fun_array[0] = &add;
fun_array[1] = ⊂
fun_array[2] = &mult;
fun_array[3] = &div;
// A little test
std::cout << fun_array[2](3, 3) << " " << fun_array[3](3,3) << " " << fun_array[1](3,3)
<< std::endl;
return 0;
}
In c++ you can also create an std::vector of functions pointer ... or any containers from the std libraries of "Tpointers".