Initialization of pointer arrays • Problem: write a function month_name(n) , returning the name of the n -th month (in the form of a pointer to a string) • We will use a static array • month_name contains an array of pointers to 13 strings • … ret...
Initialization of variables • A variable may also be initialized in its declaration • Syntax: type name = expression; • Examples: char esc = '\\'; int i = 7*8; int limit = MAXSIZE+1; float eps = 1.0e-5; char msg[] = "warning: "; • For not automatic variables: the initialization is done on...
Itoa A conversion from an i nteger to A SCII string /* itoa: convert n to characters in s */ void itoa(int n, char s[]) { int i, sign; if ((sign = (n 0); /* delete it */ if (sign) s[i++] = '-'; /* n was negative */ s[i] = '\0'; /* mark the end of ...
#define CHAR_BIT 8 /* number of bits in a char */ #define SCHAR_MIN (-128) /* minimum signed char value */ #define SCHAR_MAX 127 /* maximum signed char value */ #define UCHAR_MAX 0xff /* maximum unsigned char value */ #ifndef _CHAR_UNSIGNED #define CHAR_MIN SCHAR_MIN /* mimimum char value */ #defi...
malloc and free • Allocating memory: void *malloc(size_t size); if unsuccessful, returns NULL • Freeing memory: void free(void *block); • Memory is allocated on the heap #include /* printf */ #inc...
new and delete • new and delete are operators that create and destroy an object • Syntax for a single object: = new ; delete ; • Example for a single object: int *ptr; /* int or any non-function...
Passing t wo-dimensional arrays to functions • At least the number of colums should be defined in the parameter declaration • The number of rows is irrelevant • The function gets a pointer to an array of rows • Passing daytab to a function f : f(i...
Pointers to structures typedef struct { int k; double x; } my_str; my_str *p; p = (my_str*)malloc(sizeof(my_str)); if (p==NULL) fprintf(stderr,"Out of memory...\n"); else { (*p).k = 9; /* *p.k is incorrect */ p-k = 10; /* works like (*p)....
Pointers vs. multi- dimensional arrays • For these definitions: int a[10][20]; and int *b[10]; • Expressions a[3][4] and b[3][4] refer to a single int . • But: - a is a true two-dimensional array with 200 integers - the location of a[row,col] in memory...
Standards • C - The C programming language, K&R, (1978) - ANSI C or C89 (1989) - C99 (1999) - C1X (2011/12) • C++ - C++98 (1998) - C++03 (2003) - C++TR1 (2007) - C++11 (2011, ISO/IEC 14882:2011) ...
