CODEWITHSUNDEEP
cfunction
NewCoder
NewCoder

Reputation: 183

function prototype using in function without pointer

My instructor mentioned using function as parameter in other function. (I don't mean using pointers. Is it possible ? I show below) I don't understand what he did. Can anyone explain with examples ? Thank you all appreciated answers.

using style is:

    int test(double abc(double)){
    // bla bla
}

function is:

double abc(double n){
// function main
}

The examples is written by me I'm not so sure they're right.

Upvotes: 4

Views: 138

Answers (2)

mzu
mzu

Reputation: 723

if you use a pointer you can call the function later in function test.

typedef double (*func_type)(double);

int test(func_type func) {
// bla bla 
   cout << func(3);
}

// 2 call
test(double_func)

If you want to call the function before calling test, then just define:

int test(double) {
// bla bla
   cout << double;
}

// 2 call
test(double_fun(2.0));

correct choice depends on your intentions

Upvotes: -1

ouah
ouah

Reputation: 145829

This function declaration:

int test(double abc(double))
{
    // bla bla
}

is equivalent to:

int test(double (*abc)(double))
{
    // bla bla
}

The abc parameter is a parameter of function pointer type (double (*)(double))).

For C Standard reference:

(C99, 6.7.5.3p8) "A declaration of a parameter as "function returning type" shall be adjusted to "pointer to function returning type", as in 6.3.2.1."

Upvotes: 4

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