Slide 1.26

Introduction to QtCreator. Can show creating a new project, advertise
Qt as a cross platform frame- work (with many extension to c++),
mobile android/ios... games+applications.

/*
* hello.cpp
* This program prints a welcome message
* to the user.
*/
#include<iostream>
int main()
{
	std::cout << "Hello, world!" << std::endl;
	return 0;
}
----------------------------------------------------------------------

Slide 1.27

cc -c main.cpp

cc main.o -o tddd86

./tddd86


----------------------------------------------------------------------
Slide 1.28:

Show the effect of return value (from terminal with $?)

----------------------------------------------------------------------
Slide 1.34:

/*
 * main.cpp
 * This program introduces pointers and references.
 */
#include<iostream>

int main()
{
    int a[100];
    int* p= a;
    a[0]=12;
    std::cout << a[0] << " " << p[0] << std::endl;
       
    return 0;
}

----------------------------------------------------------------------
Slide 1.35:

Do some pointer arithmetic with p (set some more value in a);
----------------------------------------------------------------------
Slide 1.35:

show the similitude between "int* const" and "int& ":

// int b = 10;
// int& r;
// int& r=b;

// std::cout << "r= " << r << ", b=" << b << ", p=" << p << std::endl;
// b = 12;
// std::cout << "r= " << r << ", b=" << b << ", p=" << p << std::endl;
----------------------------------------------------------------------
Slide 1.36:


show "using namespace std;"

----------------------------------------------------------------------
Slide 1.37:

Show functions:
int max( int a , int b )
{
	return ( a < b ) ? b : a ;
}

struct point
{
	int x , y ;
	int max ( )
	{
		return max( x , y ) ;
	}
} ;

// Then show p u b l i c / p r i v a t e
----------------------------------------------------------------------
Slide 1.39:

int themax(int a, int b)
{
  if(a > b)
    return a;
  else
    return b;
}

int main()
{
  int bigger= themax(17, 42);
  cout << "max= " << bigger << endl;
  return 0;
}

Switch the declaration between main and max

----------------------------------------------------------------------
Slide 1.40:

Add the prototype.

----------------------------------------------------------------------
Slide 1.43:

Show the swap function in action. Use debug.

----------------------------------------------------------------------
Slide 1.43:

Show returning more than two values
void minmax (int a, int b, int& min, int& max)
{
...
}

Large object

struct t
{
	int a[100];
};

void this_does_copy(t v)
{
	std::cout << v.a << std::endl;
}

void this_does_not_copy(t& v)
{
	std::cout << v.a << std::endl;
}

intmain(int argc, char ∗∗argv)
{
 tt1;

 std::cout << t1.a << std::endl;

 this_does_copy(t1);

this_does_not_copy(t1);
}

----------------------------------------------------------------------
Slide 1.43:

Show the compilation error

void grow (const int& age) {
     age = age + 1 ;
}

int main ( ) {
    int age = 20 ;
    grow(age) ;
    return 0 ;
}
----------------------------------------------------------------------