3.6. Definitions and Uses¶

Pulling together all the code fragments from the previous section, the whole program looks like this:

#include <iostream>
using namespace std;

void newLine () {
  cout << endl;
}

void threeLine () {
  newLine ();  newLine ();  newLine ();
}

int main () {
  cout << "First Line." << endl;
  threeLine ();
  cout << "Second Line." << endl;
  return 0;
}

This program contains three function definitions: newLine, threeLine, and main.

Inside the definition of main, there is a statement that uses or calls threeLine. Similarly, threeLine calls newLine three times. Notice that the definition of each function appears above the place where it is used.

This is necessary in C++; the definition of a function must appear before (above) the first use of the function. You should try compiling this program with the functions in a different order and see what error messages you get.

Q-2: Which of the following is a correct function header (first line of a function definition)?

void printName()
This function header is missing a {, which is needed to begin defining the function.
totalCostAfterTax () {
This function header is missing a return type.
void todaysWeather () {
Correct!
void finalGrade {
This function header is missing parentheses. Even if a function does not take in any parameters, empty parentheses should be used.

Construct a block of code that correctly defines a the addTwo function.

        void addTwo(int x) {

void addTwo(int x); #distractor

void addTwo(int x) #distractor

 int plustwo = x + 2;

 cout << plustwo;

}

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3.6. Definitions and Uses¶