Functions

Defining Functions

#include <stdio.h>

// you can define functions up here
// must state return type and types for the formal parameters
int addOne(int value){
    return value + 1;
}


int main(){

    int num = 10;
    int result = addOne(num);
    result = addOne(result);

    printf("You started with %d.\n", num);
    printf("Now you have %d.\n", result);

    printf("\n");
    return 0;
}

Function Prototyping

#include <stdio.h>

// we could just prototype the functions up here
// for function prototyping, we only need to state the name and types
// stating parameter identifiers is optional
int addOne(int);




int main(){
    int num = 10;
    int result = addOne(num);

    printf("Start: %d\n", num);
    printf("End: %d\n", result);

    printf("\n");
    return 0;
}


// then define them down here
int addOne(int value){
    return value + 1;
}