using functions from outside a class [duplicate] - c++

Question

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Why is my HelloWorld function not declared in this scope?
(11 answers)
Closed 2 years ago.
First of forgive me if this has been answered, i could not find it.
i m pretty new to C++ and programming in general just fumbling my way thorough. I created a class called "Angle". outside of this class i have a function to test input from user to make sure its an integer called "isInt". But i keep getting an error "identifier not fund" if i try to use the isInt function inside the Angle class. do i have no choice but to repeat the code for isInt inside the class ?
Thanks in Advance
Bellow is my code for the class and the function
class Angle {
private:
int degrees;
float minutes;
char direction;
public:
//Setters
void setDegrees(int x) {
degrees = x;
}
void setMinutes(float y) {
minutes = y;
}
void setDirection(char z) {
direction = z;
}
//Getters
int getDegrees() {
return degrees;
}
float getMinutes() {
return minutes;
}
char getDirection() {
return direction;
}
//Constructors
Angle() {
degrees = -1;
minutes = -1;
direction = NULL;
}
//Member Functions
void getAngleFromUser() {
bool test = false;
std::string temp;
std::cout << "Please input an angle value (degrees and minutes)\n";
while (test != true) {
std::cout << "Please input and angle in degrees (it must be an integer): ";
std::cin >> temp;
test = isInt(temp);
}
setDegrees(std::stoi(temp));
}
};
bool isInt(std::string input)
{
if (input.find_first_not_of("1234567890") != std::string::npos) {
std::cout << "invalid input. please input integer\n";
return false;
}
else {
return true;
}
}

Answer 1

To use any function you must declare/define it before using it.
i.e if you write
bool isInt(std::string); before defining your class, your problem will be solved.
Other things
your getters (getDegrees/Minutes/Direction) should be constant.
input argument should be constant.
why don't you include isInt in your class as a private function to encapsulate it?
And what do you mean by Null to be assigned to a character? you may mean \0
while (test != true) equiv while(!test)