puts(¨string¨)  // print


DEFINES #define C (int)
	#define X(i) x[i]
	#define Y(i,j) i * j
		C X(3) + Y(i,7);
gets transformed into the code
		(int) x[3] + i * 7;

#define abc(x,y) # x "+" # y
abc(123,xyz)   -->  "123+xyz" 
espaco -->  ##

COMMENT  between #if 0 and #endif lines.

char str[] = "292348"; // a char array with 7 elements (why?); str[0] = 'T' is ok
char *pstr = "2983"; // a string literal; *pstr = '4' gives a runtime error

char str[20] = "AB"; // same as char str[20] = { 'A','B',0 }; or char str[20] = { 65,66,0 };
defines a string that can hold up to 19 characters (space must be reserved for the 0 terminator), initialized with the
two character string AB.


value  name 	meaning 			escape sequence
0 	NUL 	null character (end of string) 		\0
7 	BEL 	terminal bell 				\a
8 	BS 	backspace 				\b
9 	HT 	horizontal tab 				\t
10 	LF 	new line 				\n
12 	FF 	form feed (new page) 			\f
13	CR 	carriage return				\r
27 	ESC	 escape 				\e


int a[100];
int *pa = &a[30]; // same as int *pa = a + 30;  //acede ao a[30]
int *pA = &a[-2]; // same as int *pA = a - 2;


STRUCT
struct dot d; // a dot structure (RESERVES SPACE FOR THE STRUCTURE)
struct dot *pd; // a pointer to a dot structure (DOES NOT RESERVE SPACE FOR THE STRUCTURE)
pd = &d; // set the pointer to point to the structure (now it can be safely used)
d.x = 3; // set the x field to 3
pd->color = 5; // set the color field to 5
d.next = NULL; // set the next field to NULL (a special address that points to nothing)


enum color { black,red,green,blue = 4 }; // can have 4 values: black, red, green, and blue, respectively
with numerical values 0, 1, 2, and 4.


sizeof(1 + 2) is the number of bytes needed to store the result of the expression 1 + 2

extern int global_var; // variable that may, or may not, be defined in the same source code file

static int global_var; // global variable that is visible only to the functions of the same source code file


SLIDE 49