Identifier not found when calling a function under a function - c++

Question

I trying to develop a program that displays a 12 hour and 24 hour clock at the same time. But whenever I compile, I get a build error saying 'GetAM_PM': identifier not found. I get this error on line 26 in spite of using the same variable from my function parameter. What could be the root of this problem? Here is my code:
#include <iostream>
#include<ctime>
#include<cstdlib>
using namespace std;
//converting it into 12 hour format
int TwelveHourFormat(int twelve_hours) {
return (twelve_hours == 0 || twelve_hours == 12) ? 12 :
twelve_hours % 12;
}
//printing the 12 hour format
void Display_12_HourFormat(int seconds, int minutes, int
twelve_hours) {
cout.fill('0');
cout << TwelveHourFormat(twelve_hours) << ":" << minutes << ":"
<< seconds << " " << GetAM_PM(twelve_hours);
}
//printing the 24 hour format
void Display_24_HourFormat(int seconds, int minutes, int
twenty_four_hours) {
cout.fill('0');
cout << twenty_four_hours << ":" << minutes << ":" << seconds;
}
void AddHour(int hour) {
hour = (hour + 1) % 24;
}
void AddMinute(int hour, int min) {
if (min == 59) {
AddHour(hour);
}
min = (min + 1) % 60;
}
void AddSecond(int min, int sec) {
if (sec == 59) {
AddMinute(min, sec);
}
sec = (sec + 1) % 60;
}
// function return AM/PM respect to hour of time
string GetAM_PM(int twelve_hours) {
return twelve_hours >= 12 ? "PM" : "AM";
}
// This method prints the menu options
void DisplayMenu() {
cout << "Chada Tech Clocks Menu" << endl;
cout << "[1] Add one hour" << endl;
cout << "[2] Add one minute" << endl;
cout << "[3] Add one second" << endl;
cout << "[4] Exit program" << endl;
}
int main()
{
int seconds, minutes, hours;
//obtains current time in seconds
time_t total_seconds = time(0);
//getting values of seconds, minutes and hours
struct tm ct;
localtime_s(&ct, &total_seconds);
seconds = ct.tm_sec;
minutes = ct.tm_min;
hours = ct.tm_hour;
// Variable declared
int option;
do
{
// DisplayMenu function is called
DisplayMenu();
cin >> option;
// If user input is 1, Clock function is called
if (option == 1) {
TwelveHourFormat(hours);
AddHour(hours);
GetAM_PM(hours);
Display_12_HourFormat(seconds, minutes, hours);
Display_24_HourFormat(seconds, minutes, hours);
}
// If the option is 2, the Clock function is called
else if (option == 2) {
AddMinute(minutes, seconds);
GetAM_PM(hours);
}
// If the option is 3, the Clock function is called
else if (option == 3) {
AddSecond(minutes, seconds);
GetAM_PM(hours);
}
// If the option is 4, exit message prints and application
stops running
else if (option == 4) {
cout << "You have exited the application.";
break;
}
else {
cout << "You have entered an invalid input." << endl;
}
} while (option != 4);
}

Answer 1

You need to declare GetAM_PM before you define Display_12_HourFormat. Otherwise it'll not be known by the compiler at the time it parses the Display_12_HourFormat function in which GetAM_PM is called.

Answer 2

Just move these lines to the beginning, before any other function:
// function return AM/PM respect to hour of time
string GetAM_PM(int twelve_hours) {
return twelve_hours >= 12 ? "PM" : "AM";
}
It is not this case, but if you end up with circular dependency, try to declare the methods in a .h or forward declare the methods in the code.