Lessons

Variables :

int main() { int number; //Declare the variable number which is an integer (int) number = 42; //Assign the value 42 to my variable number numer = 3 + 3; //Assign the value 6 to my variable number char letter; //Declare the variable letter which is a character (char) letter = 'A'; //Assign the value A to my variable letter return (0); }

Functions :

The main function in C is the first function called in your program.
A function is composed in this order by a return value, the name and the parameters.


void my_putchar(char c) //The function is called my_putchar, returns nothing and takes a char in parameter
{
//c == 'A'
}




int main() //The function is called main, returns an integer and takes no parameters
{
my_putchar('A'); //Call the function my_putchar with the char 'A' in parameter
return (0); //The function return the integer 0
}


Conditions :


int main()
{
int a = 0, b = 12;


if (a == 0)
{
//If the variable a is equal to 0 the code goes here
}
else if (b != 12)
{
//Else if the variable b is different to 12 it goes here
}
else
{
//Else it goes here
}
return (0);
}


Loops :

int main()
{
for(int i = 0; i <= 5; i++) //The for loop
{
//Do something
}
//After the loop i == 5


char c = 'A'; //char c = 65 is the same (ASCII table)
while (c <= 'D') // The while loop
{
c++;
}
//After the loop c == 'D' or c == 68 (ASCII table)
return (0);
}

Using my_putchar :

int main()
{
char print = 'a';

my_putchar(print); //Displays a
my_putchar('a'); //Displays a
my_putchar(97); //Displays a (ASCII table, 'a' is the same as 97)
my_putchar('7'); //Displays 7
print = print + 1;
my_putchar(print); //Displays b
return (0);
}

ASCII Table :