MVRT Vision Trainings Examples

MVRT Vision Trainings Examples Week 4

basicFunctions.cpp

#include <iostream>

// “Prototypes” help the compiler identify functions that are in the file
int sum (int a, int b);
double diff (double a, double b);

int main ()
{
	std::cout << sum (1, 2) << "\n";
	std::cout << diff (5.2, 2.7) << "\n";
}

int sum (int a, int b)
{
	return (a + b);
}

double diff (double a, double b)
{
	return (a - b);
}

basicPointers.cpp

#include <iostream>

int main ()
{
	int processId = 123456;
	
	// Note: upper case
	int* pid = NULL;
	pid = &processId;
	
	std::cout << processId << "\n";
	std::cout << pid << "\n";
	std::cout << *pid << "\n";
	std::cout << &pid << "\n";
}

basicStructs.cpp

#include <iostream>
#include <string>

// Similar to Java's class
// Note: C++ has classes too, which we'll talk about later
struct Human
{
    int age;
    std::string name;
};

int main ()
{
    Human bob;
    bob.age = 15;
    bob.name = "Bob Loblaw lobs law bombs while blogging on his law blog";
    
    Human* sally;
    sally->age = 18;
    sally->name = "Sally Kim";
    
	std::cout << "Bob's age:   " << bob.age     << "\n";
	std::cout << "Sally's age: " << sally->age  << "\n";
	std::cout << "Bob's name:  " << bob.name    << "\n";
	std::cout << "Sally's age: " << sally->name << "\n";
}

constantVariables.cpp

int main ()
{
	const int PIXELS_PER_INCH = 640;
	// PIXELS_PER_INCH = 1280; // ERROR
}

ConstantVariables.java

public class ConstantVariables {
	
	private final int PIXELS_PER_INCH = 640;
	
	public static void main (String[] args) {
		// PIXELS_PER_INCH = 1280; // ERROR
	}
}

globalLocalVariables.cpp

#include <iostream>

int signalId = 123; // “global variable”, “field”

int main ()
{
	int signalId = 456; // “local variable”
	std::cout << signalId << "\n";
}

helloWorld.cpp

#include <iostream>
#include <string>

int main ()
{
    std::string phrase = "Hello World";
    
    std::cout << phrase << "\n";

    return 0;
}

otherDataTypes.cpp

#include <string>

int main ()
{
    // 1 byte is 8 bits

    // 16 bits (–32,768 to 32,767)
    short twoBytes = 0;

    // 32 bits (–2,147,483,648 to 2,147,483,647)
    long fourBytes = 0;

    // 64 bits (–9,223,372,036,854,775,808 to 9,223,372,036,854,775,807)
    // Depends on the compiler and machine
    long long int eightBytes = 0LL;

    // 32 bits
    std::string word = "Hello World";

    // Size in bytes depends on number and types of elements
    int integerArray[3] = {0, 1, 2};

    return 0;
}

primitiveDataTypes.cpp

int main ()
{
    // 1 byte is 8 bits

    // 32 bits (–2,147,483,648 to 2,147,483,647)
    int fourBytes = 0;

    // 32 bits (Positive or Negative: 1.40129846432481707e-45 to 3.40282346638528860e+38)
    float fourBytesDecimal = 0.0f;

    // 64 bits (Positive or Negative: 4.94065645841246544e-324d to 1.79769313486231570e+308d)
    double eightBytesDecimal = 0.0f;

    // 8 bits
    char singleLetter = 'a';

    // 1 bit (True or False)
    bool isTrue = false;

    // wchar_t is a primitive data type, but don't use it because it's not very portable

	// Also void data type, but variables cannot be of type void

    return 0;
}