Various
Statements used in ‘C’ language:
I
/ O Statements:
An
I/O statement is related to the operations to the performed on I/O device. There are two types I/O functions are used
frequently in ‘c’ language. They are ‘printf’
and ‘scanf’.
These two functions are available in the header file
‘stdio.h’.
printf:
This function is used to display the information on the screen .
It is a precompiled library function in ‘C’ language
prototyped in ‘stdio.h’.
The syntax of printf is
printf(“string
/ formatted string / escape sequences”, value 1, value 2,…);
printf statement
displays the information available in the string as usual. If it is a formatted
character such as %d or %c etc the value corresponding to it substituted. If we
use an escape sequence character the meaning is changed.
Example : printf(
“Welcome to C”); à welcome to C
printf(“%d”, 4*20) à 80
printf(“%o”,40) à
050
printf (“%d”,’A’) à
65
Scanf: It is an input function which is used to read
information from keyboard into a memory location (address of a variable).
It is a precompiled library function in ‘C’ language
prototyped in stdio.h.
The
syntax of scanf is as follows:
Scanf(“formatted
string”,&u1,&u2,…);
To specify the address of a variable
we can use operator ampersand (&)
which stands for address of.
We can use scanf function in a ‘c’
program we have to use only formatted
characters no others are not allowed.
Example
: int a,b;
Float c;
longdouble d;
scanf(“%d%d%f%lf”,&a,&b,&c,&d);
Conversion
specifications that we need presently are as follows
%d àinteger representation
%f à float representation
%c à character representation
%u àunsigned integer or address
representation
%s à
String representation
