Passing the address of structure as an argument to function −The Address of the structure is passed as an argument to the function.It is collected in a pointer to structure in function header.AdvantagesNo wastage of memory as there is no need of creating a copy againNo need of returning the values back as the function can access indirectly the entire structure and work on it.Example#include struct date{    int day;    int mon;    int yr; }; main (){    struct date d= {02, 01, 2010};    display (&d);    getch (); } display (struct date *dt){    printf("day = ... Read More

Passing individual members as arguments to function −Each member is passed as an argument in the function call.They are collected independently in ordinary variables in function header.Example#include //Declaring structure// struct student{    int s1,s2,s3; }s[5]; //Declaring and returning Function// void addition(int a,int b,int c){    //Declaring sum variable and For loop variable//    int i,sum;    //Arithmetic Operation//    for(i=1;i

Typedef‘C’ allows to define new datatype names using the ‘typedef’ keyword. Using ‘typedef’, we cannot create a new datatype but define a new name for already existing type.Syntaxtypedef datatype newname;Exampletypedef int bhanu; int a; bhanu a; %dThis statement tells the compiler to recognize ‘bhanu’ as another name for ‘int’.‘bhanu’ is used to create another variable ‘a’ .‘bhanu a ‘declares ‘a’ as a variable of type ‘int’.Example#include main (){    typedef int hours;    hours h; //int h;    clrscr ();    printf("Enter hours”);    scanf ("%d”, &h);    printf("Minutes =%d”, h*60);    printf("Seconds = %d”, h*60*60);    getch (); ... Read More

Using strrev() functionThe function is used for reversing a string.The reversed string will be stored in the same string.Syntaxstrrev (string)Before working on reversing the string without using function, let’s have a look on how to reverse a string using string function strrev(), so that we can easily find the difference and gets clarity on the concept −Example#include main (){    char a[50] ;    clrscr();    printf (“enter a string”);    gets (a);    strrev (a);    printf(“reversed string = %s”, a)    getch (); }Outputenter a string Hello reversed string = olleHWithout using strrev() functionNow let’s see the program ... Read More

Before going to know about how to convert upper case to lower case letters without string convert function.Let us have a look on program to convert upper to lower using convert function, then you will get a clarity on what we are doing in the program −Example#include #include int main(){    char string[50];    printf("enter a string to convert to lower case");    gets(string); /reading the string    printf("The string in lower case: %s", strlwr(string)); //strlwr converts all upper    to    lower    return 0; }Outputenter a string to convert to lower case CProgramming LangUage The string ... Read More

ProblemWhat do you mean by String to number and number to string conversion in C programming language?SolutionThere are two functions available for conversion. They are −sscanf() − convert string to numbersprintf () − used for converting number to stringString to number conversionWe can convert string to number using the sscanf() function −Syntaxsscanf (string name, “control string”, variable list)Example#include main (){    char a[20] = “02 01 2010”;    int day, mon, yr;    clrscr();    sscanf (a, “%d%d %d”, &day, &mon, &yr);    printf ( “Day =%d”, day);    printf ( “Month = %d”, mon);    printf ( “Year = ... Read More

String Library functionsThe predefined functions which are designed to handle strings are available in the library string.h. They are −strlen ()strcmp ()strcpy ()strncmp ()strncpy ()strrev ()strcat ()strstr ()strncat ()The strlen () functionIt returns the number of characters in a string.Syntaxint strlen (string name)Example#include main (){    char a[30] = “Hello”;    int l;    l = strlen (a);    printf (“length of the string = %d”, l);    getch (); }Outputlength of the string = 5The strcpy () functionIt is for copying source string into destination string.The length of the destination string >= source string.Syntaxstrcpy (Destination string, Source String);For ... Read More

Arrays of pointers (to strings)Array of pointers is an array whose elements are pointers to the base address of the string.It is declared and initialized as follows −char *a[3 ] = {"one", "two", "three"}; //Here, a[0] is a ptr to the base add of the string "one" //a[1] is a ptr to the base add of the string "two" //a[2] is a ptr to the base add of the string "three"AdvantagesUnlink the two-dimensional array of characters. In (array of strings), in array of pointers to strings there is no fixed memory size for storage.The strings occupy as many bytes as ... Read More

Pointer to functionIt holds the base address of function definition in memory.Declarationdatatype (*pointername) ();The name of the function itself specifies the base address of the function. So, initialization is done using function name.For example, int (*p) (); p = display; //display () is a function that is defined.Example 1We shall see a program for calling a function using pointer to function −#include main (){    int (*p) (); //declaring pointer to function    clrscr ();    p = display;    *(p) (); //calling pointer to function    getch (); } display (){ //called function present at pointer location    printf(“Hello”); ... Read More

Array Of PointersJust like any other data type, we can also declare a pointer array.Declarationdatatype *pointername [size];For example, int *p[5]; //It represents an array of pointers that can hold 5 integer element addressesInitializationThe ‘&’ is used for initializationFor example,int a[3] = {10,20,30}; int *p[3], i; for (i=0; i