Programming and Data Structures

236 Programming and Data Structures

7.9 THE sscanf () AND sp rin tf () FUNCTIONS

a) sscanf () The sscanf () function allows to read characters from a character array and writes them

to another array.

This function is similar to scan f () but instead from standard input it reads data from an array.

7.40 Write a program to read string from a character array.

# include <stdio.h>

# include <canio.h>

void main ()

{

char i n [10] ,out[10];

clrsc r () ;

gets(in);

sscanf (in,”% s"j>ut);

printf ("% s\n ",out);

}

Q V m i L

HELLO

HELLO

Explanation In the above program two character arrays in [10] and out [10] are declared. Thegets

() function reads the string through the terminal and it is stored in the array in [ ]. Till this time the

o u t[ ] array is empty. The sscanf () function reads characters from array in [ ] and assignes it to

array out [ ]. Thus, both the arrays contain the same string. At the end the p r i n t f () function

displays the contents of array out [ ] .

7.41 Write a program to read integers in character array, convert and assign them to integer

variable using sscanf () function.

# include <stdio.h>

# include <conio.h>

void main ()

{

int *x;

char in [10] ;

c lrsc r ();

printf ("\ n Enter Integers: " ) ;

gets(in);

sscanf ( in, "% d",x);

printf ("\ n Value of int x : % d "*x );

getcheO;

I

OUTPUT:

Enter Integers: 123

Value of int x : 123

Explanation In the above program integer is read and stored in the character array in [ ] . The

variable 'x' is declared as an integer pointer. The ssc an f () function assigns base address of array

in [ ] to pointer ' x '. The content of pointer 1 x ' is displayed using pointer notation (*).

Arrays 237

b ) sp r in t f () The s p r in t f () function is similar to th e p rin tf () function except a small difference

between them. T h ep rin tf () function sends the output to the screen where as the s p r i n t f () function

writes the values of any data type to an array of characters. The following program is illustrated

pertaining to sp rin t f ().

7.42 Writes a program to explain the use of sprintfO.

# include <stdio.h>

# include <conio.h>

void m&inO

{

int a*10;

char c - 'C ';

float p*3.14;

char spf [20];

clrscr ();

sprintf(spf,"%d %c % .2f',aj:,p);

printf ("\n%s",sp f);

getcheO;

}

P U T E U I

10 C 3.14

Explanation In the above program sprint f () stores the values of variables in the character array

spf [ ]. While sprin t f () function executes the contained variables won't be displayed on the

screen. The contents of an array spf is displayed using p rin tf () function.

7.43 Write a program to complete the string by filling the spaces with appropriate characters.

# include <stdio.h>

# include <conio.h>

void main ()

{

char name [] *"Mas er ng A SI C*;

int x=0;

clrscr ();

printf ("M astering A N S I C\n\n ");

while (name[x]!=0)

{

if(nam e[x]~32)

name[x]-getche();

else

putch(name[x]);

x++;

I

getche ();